6 ms·

I could've sworn I remember something about bash and glibc cooperating to indicate which arguments come from expanded variables but I cannot find anything on th

I could've sworn I remember something about bash and glibc cooperating to indicate which arguments come from expanded variables but I cannot find anything on the internet or in the sources. Either I'm going insane or it was an unmerged proposal.

BobbyTables2 2y ago
Seems like it would be quite painful to do that in C without heavy refactoring. Maybe a Rust alternative ?
- yjftsjthsd-h 2y ago
  Why would that be painful in C? The code is already handling all the pieces
  - pluto_modadic 2y ago
    Painful to write vs painful to audit for correctness. Writing code that you barely understand is a surefire recipe to have /no clue/ how to debug said code (because debugging it will be more complex). (let alone audit it for correctness/security).
    - yjftsjthsd-h 2y ago
      That just sounds like you don't believe it's ever possible to change existing C code, which... is a position you can argue, but I'm pretty sure that bash and glibc are actively developed to the point where I wouldn't personally commit to that position.
  - ForOldHack 2y ago
    Insert obligatory ref to "on trusting trust" what is the compiler doing? Has the pre-processor been vetted? This is looking more and more like hardware solutions are becoming more attractive.
    - yjftsjthsd-h 2y ago
      1. I don't see why you need to solve Trusting Trust to make libc and the shell more robust. 2. If we are worried about Trusting Trust, then Rust is worse; at least C has the wide range of compilers needed for diverse double-compiling and as of https://guix.gnu.org/en/blog/2023/the-full-source-bootstrap-building-from-source-all-the-way-down/ https://guix.gnu.org/en/blog/2023/the-full-source-bootstrap-... we arguably have a working solution. Rust only has a single compiler, and that compiler is used to build itself, making it the poster child for Trusting Trust targets.
      - steveklabnik 2y ago
        Rust has a second compiler, mrustc, written in C++ and that is able to bit-reproduce rustc. This has been the case for a few years now.
        yjftsjthsd-h 2y ago
        Oh, excellent; I didn't realize that was capable of building rustc. In that case, I'm wrong and Rust is just as good as C.
  - Avamander 2y ago
    Besides what has already been said in other comments, I think reality has already shown how it _is_ painful in C. It's painful to implement both safe and ergonomic. The amount of subtly incorrect and/or differing implementations doing easier things out there is just incredible.
jwilk 2y ago
It was a thing back in 1996/1997: https://sourceware.org/cgit/glibc/commit/?id=bf079e19f50d64aa5e05b5e1 https://sourceware.org/cgit/glibc/commit/?id=bf079e19f50d64a...
- PhilipRoman 2y ago
  Yeah this is exactly what I was thinking of, thanks for finding it.
- musicale 2y ago
  > "disabled later" because "it caused problems" ;-(

BobbyTables2 2y ago

Seems like it would be quite painful to do that in C without heavy refactoring. Maybe a Rust alternative ?

yjftsjthsd-h 2y ago
Why would that be painful in C? The code is already handling all the pieces
- pluto_modadic 2y ago
  Painful to write vs painful to audit for correctness. Writing code that you barely understand is a surefire recipe to have /no clue/ how to debug said code (because debugging it will be more complex). (let alone audit it for correctness/security).
  - yjftsjthsd-h 2y ago
    That just sounds like you don't believe it's ever possible to change existing C code, which... is a position you can argue, but I'm pretty sure that bash and glibc are actively developed to the point where I wouldn't personally commit to that position.
- ForOldHack 2y ago
  Insert obligatory ref to "on trusting trust" what is the compiler doing? Has the pre-processor been vetted? This is looking more and more like hardware solutions are becoming more attractive.
  - yjftsjthsd-h 2y ago
    1. I don't see why you need to solve Trusting Trust to make libc and the shell more robust. 2. If we are worried about Trusting Trust, then Rust is worse; at least C has the wide range of compilers needed for diverse double-compiling and as of https://guix.gnu.org/en/blog/2023/the-full-source-bootstrap-building-from-source-all-the-way-down/ https://guix.gnu.org/en/blog/2023/the-full-source-bootstrap-... we arguably have a working solution. Rust only has a single compiler, and that compiler is used to build itself, making it the poster child for Trusting Trust targets.
    - steveklabnik 2y ago
      Rust has a second compiler, mrustc, written in C++ and that is able to bit-reproduce rustc. This has been the case for a few years now.
      - yjftsjthsd-h 2y ago
        Oh, excellent; I didn't realize that was capable of building rustc. In that case, I'm wrong and Rust is just as good as C.
- Avamander 2y ago
  Besides what has already been said in other comments, I think reality has already shown how it _is_ painful in C. It's painful to implement both safe and ergonomic. The amount of subtly incorrect and/or differing implementations doing easier things out there is just incredible.

jwilk 2y ago

It was a thing back in 1996/1997: https://sourceware.org/cgit/glibc/commit/?id=bf079e19f50d64aa5e05b5e1 https://sourceware.org/cgit/glibc/commit/?id=bf079e19f50d64a...

PhilipRoman 2y ago
Yeah this is exactly what I was thinking of, thanks for finding it.
musicale 2y ago
> "disabled later" because "it caused problems" ;-(