The Linux kernel config system, Kconfig, uses a macro language very similar to the make build tool's macro language. There are a few differences, however. And of course, make is designed as a general-purpose build tool while Kconfig is Linux-kernel-specific. But, why would the kernel developers create a whole new macro language so closely resembling that of an existing general-purpose tool?
One reason became clear recently when Linus Torvalds asked developers to add an entirely new system of dependency checks to the Kconfig language, specifically testing the capabilities of the GCC compiler.