Bootstrapping a compiler: why?

Question

I understand how a language can bootstrap itself, but I haven\'t been able to find much reference on why you should consider bootstrapping.

The int

Answer 1

Ken Thompson's Reflections on Trusting Trust explains one of the best reasons for bootstrapping. Essentially, your compiler learn new things for every version of the compiler in the bootstrapping chain that you will never have to teach it again.

In the case he mentions, The first compiler (C1) you write has to be explicitly told how to handle backslash escape. However, the second compiler (C2) is compiled using C1, so backslash escape handling is natively handled.

The cornerstone of his talk is the possibility that you could teach a compiler to add a backdoor to programs, and that future compilers compiled with the compromised compiler would also be given this ability and that it would never appear in the source!

Essentially, your program can learn new features at every compilation cycle that do not have to be reimplemented or recompiled in later compilation cycles because you compiler knows all about them already.

Take a minute to realise the ramifications.

[edit]: This is pretty terrible way to build a compiler, but the cool factor is through the roof. I wonder if it could be manageable with the right framework?