[a2code]

I am brainstorming here.

In practice, perhaps a C program that acts as a validation test. The source code of this C program is not publicly available. Only the binary is distributed. Let us name the binary ctestbox.

When ctestbox is run, it creates a multiplicity of new text or binary files. Each of these is like a unit test.

Consider a tool that decompiles a binary. Given ctestbox, this tool should make a.out which when run, ideally creates identical text or binary files. Now you simply count the number of identical files as a metric.