include(PkgConfigWithFallback)
find_pkg_config_with_fallback(SignalProtocol
    PKG_CONFIG_NAME signal-protocol-c
    LIB_NAMES signal-protocol-c
    INCLUDE_NAMES signal/signal_protocol.h
)

include(FindPackageHandleStandardArgs)
find_package_handle_standard_args(SignalProtocol
    REQUIRED_VARS SignalProtocol_LIBRARY)