2018-03-10 13:15:01 +01:00
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#+TITLE: Bootstrapping, reproducibility, etc.
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#+AUTHOR: Vincent Ambo
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#+DATE: <2018-03-10 Sat>
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* Compiler bootstrapping
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This section contains notes about compiler bootstrapping, the
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history thereof, which compilers need it - and so on:
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** C
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** Haskell
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- self-hosted compiler (GHC)
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** Common Lisp
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CL is fairly interesting in this space because it is a language
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that is defined via an ANSI standard that compiler implementations
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normally actually follow!
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2018-03-10 15:10:10 +01:00
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CL has several ecosystem components that focus on making
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abstracting away implementation-specific calls and if a self-hosted
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compiler is written in CL using those components it can be
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cross-bootstrapped.
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2018-03-10 13:15:01 +01:00
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** Python
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* A note on runtimes
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Sometimes the compiler just isn't enough ...
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** LLVM
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** JVM
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2018-03-12 01:08:30 +01:00
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* References
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https://github.com/mame/quine-relay
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https://manishearth.github.io/blog/2016/12/02/reflections-on-rusting-trust/
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2018-03-13 00:18:32 +01:00
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https://tests.reproducible-builds.org/debian/reproducible.html
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2018-03-10 13:15:01 +01:00
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* Slide thoughts:
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1. Hardware trust has been discussed here a bunch, most recently
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during the puri.sm talk. Hardware trust is important, as we see
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with IME, but it's striking that people often take a leap to "I'm
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now on my trusted Debian with free software".
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Unless you built it yourself from scratch (Spoiler: you haven't)
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you're placing trust in what is basically foreign binary blobs.
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Agenda: Implications/attack vectors of this, state of the chicken
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& egg, the topic of reproducibility, what can you do? (Nix!)
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2. Chicken-and-egg issue
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It's an important milestone for a language to become self-hosted:
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You begin doing a kind of dogfeeding, you begin to enforce
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reliability & consistency guarantees to avoid having to redo your
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own codebase constantly and so on.
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However, the implication is now that you need your own compiler
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to compile itself.
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Common examples:
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2018-03-10 15:10:10 +01:00
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- C/C++ compilers needed to build C/C++ compilers:
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GCC 4.7 was the last version of GCC that could be built with a
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standard C-compiler, nowadays it is mostly written in C++.
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Certain versions of GCC can be built with LLVM/Clang.
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Clang/LLVM can be compiled by itself and also GCC.
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- Rust was originally written in OCAML but moved to being
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self-hosted in 2011. Currently rustc-releases are always built
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with a copy of the previous release.
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It's relatively new so we can build the chain all the way.
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2018-03-12 01:08:30 +01:00
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Notable exceptions: Some popular languages are not self-hosted,
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for example Clojure. Languages also have runtimes, which may be
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written in something else (e.g. Haskell -> C runtime)
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2018-03-13 00:18:32 +01:00
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* How to help:
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Most of this advice is about reproducible builds, not bootstrapping,
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as that is a much harder project.
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- fix reproducibility issues listed in Debian's issue tracker (focus
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on non-Debian specific ones though)
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- experiment with NixOS / GuixSD to get a better grasp on the
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problem space of reproducibility
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If you want to contribute to bootstrapping, look at
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bootstrappable.org and their wiki. Several initiatives such as MES
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could need help!
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