Cool project. Feels like writing a C compiler in Zig aligns nicely with the old "maintain it in Zig" idea that was part of Zig's early value proposition. Is that still considered a relevant goal today?
Longer term it also makes me wonder whether something like this could eventually reduce reliance on Clang/LLVM for the C frontend in zig's toolchain.
I'm not sure why people seem to be under the impression that writing a compiler means that the language the compiler is implemented in should have "low level" features. A compiler is just a text -> text translation tool if you can leverage other tools such as an assembler and never needs to access machine level instructions. E.g., Pascal compilers have traditionally been written in Pascal, hardly a language which conjures up a "low level" image. Even when an assembler isn't available, all your implementation language needs to support, in terms of "low level" features, is writing of bytes to a file.
But manipulating instruction and file formats and such can be tedious if your language doesn't have the right capabilities but it's not impossible.
> Pascal compilers have traditionally been written in Pascal, hardly a language which conjures up a "low level" image.
It may be the case that it doesn't conjure up such an image, but Pascal is approximately on the same rung as Zig or D—lower level than Go, higher level than assembly. If folks have a different impression, the problem is just that: their impression.
Pascal, as defined by Wirth, had no "low level" features. E.g., no control over memory allocation other than the language provided new/dispose, no bit operators, clunky strings of fixed size, no access to system calls, no access to assembly, not even any hex or octal constants, all features which a language allowing "low level" access is expected to have (e.g. Ada, Modula-2/3, Oberon, all Pascal-derived languages). Things like conformant array parameters showed up much later in the ISO version but were not widely adopted. No modules either but this is not a low level feature. Turbo Pascal attempted to fix all this on the PC later on and it was deservedly well loved. Still, Wirth successfully wrote Pascal compilers in Pascal without --- obviously -- having a Pascal compiler available. [Link](https://en.wikipedia.org/wiki/Pascal_(programming_language)#...)
It's because a compiler is supposed to be high-level to low-level; you already have a lower-level language to write in it, and not a higher-level one. Writing a C compiler in a higher-level language than C is going backwards.
E.g., Pascal compilers have traditionally been written in Pascal, hardly a language which conjures up a "low level" image.
How could the first Pascal compiler be compiled if it was written in Pascal, but a Pascal compiler didn't yet exist?
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[ 3.4 ms ] story [ 32.9 ms ] threadLonger term it also makes me wonder whether something like this could eventually reduce reliance on Clang/LLVM for the C frontend in zig's toolchain.
[1] https://github.com/asibahi/paella/blob/main/writeup/c19.md#u...
Still a proper programmer-flex to build another one.
But manipulating instruction and file formats and such can be tedious if your language doesn't have the right capabilities but it's not impossible.
> Pascal compilers have traditionally been written in Pascal, hardly a language which conjures up a "low level" image.
It may be the case that it doesn't conjure up such an image, but Pascal is approximately on the same rung as Zig or D—lower level than Go, higher level than assembly. If folks have a different impression, the problem is just that: their impression.
E.g., Pascal compilers have traditionally been written in Pascal, hardly a language which conjures up a "low level" image.
How could the first Pascal compiler be compiled if it was written in Pascal, but a Pascal compiler didn't yet exist?
Therein lies the magic of bootstrapping a language compiler written in the same language. Look it up.