src/lib_json/CMakeLists.txt

if(CMAKE_CXX_COMPILER_ID STREQUAL "GNU" AND CMAKE_CXX_COMPILER_VERSION VERSION_GREATER 4.1.2)
    #-Werror=* was introduced -after- GCC 4.1.2
    add_compile_options("-Werror=strict-aliasing")
endif()

include(CheckIncludeFileCXX)
include(CheckTypeSize)
include(CheckStructHasMember)
include(CheckCXXSymbolExists)

check_include_file_cxx(clocale HAVE_CLOCALE)
check_cxx_symbol_exists(localeconv clocale HAVE_LOCALECONV)

if(CMAKE_VERSION VERSION_LESS 3.0.0)
    # The "LANGUAGE CXX" parameter is not supported in CMake versions below 3,
    # so the C compiler and header has to be used.
    check_include_file(locale.h HAVE_LOCALE_H)
    set(CMAKE_EXTRA_INCLUDE_FILES locale.h)
    check_type_size("struct lconv" LCONV_SIZE)
    unset(CMAKE_EXTRA_INCLUDE_FILES)
    check_struct_has_member("struct lconv" decimal_point locale.h HAVE_DECIMAL_POINT)
else()
    set(CMAKE_EXTRA_INCLUDE_FILES clocale)
    check_type_size(lconv LCONV_SIZE LANGUAGE CXX)
    unset(CMAKE_EXTRA_INCLUDE_FILES)
    check_struct_has_member(lconv decimal_point clocale HAVE_DECIMAL_POINT LANGUAGE CXX)
endif()

if(NOT (HAVE_CLOCALE AND HAVE_LCONV_SIZE AND HAVE_DECIMAL_POINT AND HAVE_LOCALECONV))
    message(WARNING "Locale functionality is not supported")
    if(CMAKE_VERSION VERSION_GREATER_EQUAL 3.12.0)
        add_compile_definitions(JSONCPP_NO_LOCALE_SUPPORT)
    else()
        add_definitions(-DJSONCPP_NO_LOCALE_SUPPORT)
    endif()
endif()

set(JSONCPP_INCLUDE_DIR ../../include)

set(PUBLIC_HEADERS
    ${JSONCPP_INCLUDE_DIR}/json/config.h
    ${JSONCPP_INCLUDE_DIR}/json/forwards.h
    ${JSONCPP_INCLUDE_DIR}/json/json_features.h
    ${JSONCPP_INCLUDE_DIR}/json/value.h
    ${JSONCPP_INCLUDE_DIR}/json/reader.h
    ${JSONCPP_INCLUDE_DIR}/json/version.h
    ${JSONCPP_INCLUDE_DIR}/json/writer.h
    ${JSONCPP_INCLUDE_DIR}/json/assertions.h
)

source_group("Public API" FILES ${PUBLIC_HEADERS})

set(jsoncpp_sources
    json_tool.h
    json_reader.cpp
    json_valueiterator.inl
    json_value.cpp
    json_writer.cpp
)

# Install instructions for this target
if(JSONCPP_WITH_CMAKE_PACKAGE)
    set(INSTALL_EXPORT EXPORT jsoncpp)
else()
    set(INSTALL_EXPORT)
endif()


if(BUILD_SHARED_LIBS)
    if(CMAKE_VERSION VERSION_GREATER_EQUAL 3.12.0)
        add_compile_definitions(JSON_DLL_BUILD)
    else()
        add_definitions(-DJSON_DLL_BUILD)
    endif()
endif()

add_library(jsoncpp_lib ${PUBLIC_HEADERS} ${jsoncpp_sources})
set_target_properties( jsoncpp_lib PROPERTIES
    OUTPUT_NAME jsoncpp
    VERSION ${JSONCPP_VERSION}
    SOVERSION ${JSONCPP_SOVERSION}
    POSITION_INDEPENDENT_CODE ON
)

# Set library's runtime search path on OSX
if(APPLE)
    set_target_properties(jsoncpp_lib PROPERTIES INSTALL_RPATH "@loader_path/.")
endif()

# Specify compiler features required when compiling a given target.
# See https://cmake.org/cmake/help/v3.1/prop_gbl/CMAKE_CXX_KNOWN_FEATURES.html#prop_gbl:CMAKE_CXX_KNOWN_FEATURES
# for complete list of features available
if(CMAKE_CXX_STANDARD EQUAL "11")
target_compile_features(jsoncpp_lib PUBLIC
        cxx_std_11 # Compiler mode is aware of C++ 11.
        #MSVC 1900 cxx_alignas # Alignment control alignas, as defined in N2341.
        #MSVC 1900 cxx_alignof # Alignment control alignof, as defined in N2341.
        #MSVC 1900 cxx_attributes # Generic attributes, as defined in N2761.
        cxx_auto_type # Automatic type deduction, as defined in N1984.
        #MSVC 1900 cxx_constexpr # Constant expressions, as defined in N2235.
        cxx_decltype # Decltype, as defined in N2343.
        cxx_default_function_template_args # Default template arguments for function templates, as defined in DR226
        cxx_defaulted_functions # Defaulted functions, as defined in N2346.
        #MSVC 1900 cxx_defaulted_move_initializers # Defaulted move initializers, as defined in N3053.
        cxx_delegating_constructors # Delegating constructors, as defined in N1986.
        #MSVC 1900 cxx_deleted_functions # Deleted functions, as defined in N2346.
        cxx_enum_forward_declarations # Enum forward declarations, as defined in N2764.
        cxx_explicit_conversions # Explicit conversion operators, as defined in N2437.
        cxx_extended_friend_declarations # Extended friend declarations, as defined in N1791.
        cxx_extern_templates # Extern templates, as defined in N1987.
        cxx_final # Override control final keyword, as defined in N2928, N3206 and N3272.
        #MSVC 1900 cxx_func_identifier # Predefined __func__ identifier, as defined in N2340.
        #MSVC 1900 cxx_generalized_initializers # Initializer lists, as defined in N2672.
        #MSVC 1900 cxx_inheriting_constructors # Inheriting constructors, as defined in N2540.
        #MSVC 1900 cxx_inline_namespaces # Inline namespaces, as defined in N2535.
        cxx_lambdas # Lambda functions, as defined in N2927.
        #MSVC 1900 cxx_local_type_template_args # Local and unnamed types as template arguments, as defined in N2657.
        cxx_long_long_type # long long type, as defined in N1811.
        #MSVC 1900 cxx_noexcept # Exception specifications, as defined in N3050.
        #MSVC 1900 cxx_nonstatic_member_init # Non-static data member initialization, as defined in N2756.
        cxx_nullptr # Null pointer, as defined in N2431.
        cxx_override # Override control override keyword, as defined in N2928, N3206 and N3272.
        cxx_range_for # Range-based for, as defined in N2930.
        cxx_raw_string_literals # Raw string literals, as defined in N2442.
        #MSVC 1900 cxx_reference_qualified_functions # Reference qualified functions, as defined in N2439.
        cxx_right_angle_brackets # Right angle bracket parsing, as defined in N1757.
        cxx_rvalue_references # R-value references, as defined in N2118.
        #MSVC 1900 cxx_sizeof_member # Size of non-static data members, as defined in N2253.
        cxx_static_assert # Static assert, as defined in N1720.
        cxx_strong_enums # Strongly typed enums, as defined in N2347.
        #MSVC 1900 cxx_thread_local # Thread-local variables, as defined in N2659.
        cxx_trailing_return_types # Automatic function return type, as defined in N2541.
        #MSVC 1900 cxx_unicode_literals # Unicode string literals, as defined in N2442.
        cxx_uniform_initialization # Uniform initialization, as defined in N2640.
        #MSVC 1900 cxx_unrestricted_unions # Unrestricted unions, as defined in N2544.
        #MSVC 1900 cxx_user_literals # User-defined literals, as defined in N2765.
        cxx_variadic_macros # Variadic macros, as defined in N1653.
        cxx_variadic_templates # Variadic templates, as defined in N2242.
)
else()
    set(CMAKE_CXX_STANDARD 98)
    target_compile_features(jsoncpp_lib PUBLIC)
endif()

install(TARGETS jsoncpp_lib ${INSTALL_EXPORT}
    RUNTIME DESTINATION ${CMAKE_INSTALL_BINDIR}
    LIBRARY DESTINATION ${CMAKE_INSTALL_LIBDIR}
    ARCHIVE DESTINATION ${CMAKE_INSTALL_LIBDIR}
)

if(NOT CMAKE_VERSION VERSION_LESS 2.8.11)
    target_include_directories(jsoncpp_lib PUBLIC
        $<INSTALL_INTERFACE:${CMAKE_INSTALL_INCLUDEDIR}>
        $<BUILD_INTERFACE:${CMAKE_CURRENT_LIST_DIR}/${JSONCPP_INCLUDE_DIR}>
        $<BUILD_INTERFACE:${PROJECT_BINARY_DIR}/include/json>
    )
endif()