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Comment by withinboredom | Hacker News Reader

Isn’t it impossible to have truly from-scratch reproducible builds? IIRC, you have to trust the compiler which can’t be built from scratch.

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You can bootstrap the compiler. It's a chore but not impossible. More usefully, you can check that your builds are identical to other people's, so at least your compiler isn't uniquely compromised.

> You can bootstrap the compiler. It's a chore but not impossible.

And specifically, only one person needs to do this once... I'm surprised there isn't some project doing this...

There is: https://savannah.nongnu.org/projects/stage0/

I don’t think it’s possible since you’d need the original compilers from the 70’s and bootstrap other compilers up to a modern one. Otherwise your existing compiler could taint your new one.

Many years ago I wrote a C compiler in assembly language. It wasn't hard, and C hasn't changed that much. The complexity in modern compilers is in the optimisation, which you don't need if you're bootstrapping. It's not impossible.

A pragmatic approach!

It'd be a fun exercise to write a tiny Forth in machine code (sans assembler) and use it to write enough of a C compiler to build tcc, or something along those lines. From there I think you can chain old (but accessible) gcc versions up to modern gcc.

No, you only need two compilers that have not been subverted by the same adversary.

https://www.schneier.com/blog/archives/2006/01/countering_tr...

That’s a good point

There are people who spend time trying to solve this issue!

https://bootstrappable.org/

https://www.gnu.org/software/mes/

The idea here, is that if you can get a very basic C compiler, you can start building TinyCC, and eventually build a pre-C++ version of GCC, and from there build up to modern GCC. This is a lot easier said than done of course, but not quite as bad as needing the original compilers from the 70s!

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