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Rust-Written Apple DRM Linux Kernel Driver Renders First Cube

bointles 4y ago
Makes me wonder who rendered the first cube in the real world. Ancient dice enthusiasts perhaps?
sylware 4y ago
I wonder if rust has not the shortcomings of C: integer promotion, implicit casts (no split between compile-time casts/runtime casts), 1 bazillion of loop keywords, switch, enum, _generic, typeof, no explicit number of bits for primitive types, etc. I am still not motivated to read the latest rust specs (I did that a long time ago and stoped because I got serious nonos, like implicit heavy free memory, or strings hardcoded in the syntax).
- remexre 4y ago
  - Integer promotion -- Nope, you need to explicitly cast; integer _literals_ get their type inferred, though. - Implicit casts It has the following coercions: + Subtyping, which is based on lifetimes, not inheritance -- e.g. I can use a global array somewhere an array with a shorter lifetime is required + unique references to shared references, unique references to mut pointers, shared references to const pointers, mut pointers to const pointers &mut ---> & | | v v *mut ---> *const + "deref coercion" -- basically, if you have a smart pointer (e.g. a reference counting one), you can get a reference out of it + "unsizing coercions" -- if you have some pointer type that points to e.g. an array of known size, and you want to change it to a (bounds-checked!) pointer to an array of unknown size (a slice, in Rust parlance), that coercion occurs + function types to function pointer types + the ! type to any other type -- there are no values of the ! type, so this is sound (it's the type that e.g. exit() returns) - loop keywords -- it's just for and while, not even do-while - switch -- It has real ML-style pattern-matching, with extra goodies for pattern-matching on arrays more easily. This doesn't have the fallthrough problems of C, and is more expressive to boot. - enum -- Again, the real ML-style design. Typesafe, and _far_ more expressive. - _Generic -- Another ML-family design :) This time via traits, which are similar to typeclasses in languages that have those instead. Think, "interfaces, but don't require a vtable (unless the programmer requests one)" - typeof -- Nope, though there's (ML-family-style again!) type inference, so the cases where it'd be necessary in e.g. C macros just aren't a problem. - No explicit number of bits -- the builtin types are u8, i32, f64, etc. -- the only ambiguously-sized integers are isize/usize, which I believe are specified to be the same size as size_t; I don't know that there's a pointer-sized integer type for platforms with larger pointers than size_t's (e.g. ARM Morello and other CHERI CPUs) Which language(s) do you like more for writing this kind of systems program?
  - sylware 4y ago
    come on... with all that neither rust nor C. It makes me want to send all that to hell and write assembly.
metadat 4y ago
Note: In this context, DRM stands for "Direct Rendering Manager" [driver]. It threw me for a loop at first, "What on earth does the Linux Kernel and Rust have to do with Digital Rights Management / copy protection!?"

Makes me wonder who rendered the first cube in the real world. Ancient dice enthusiasts perhaps?

I wonder if rust has not the shortcomings of C: integer promotion, implicit casts (no split between compile-time casts/runtime casts), 1 bazillion of loop keywords, switch, enum, _generic, typeof, no explicit number of bits for primitive types, etc. I am still not motivated to read the latest rust specs (I did that a long time ago and stoped because I got serious nonos, like implicit heavy free memory, or strings hardcoded in the syntax).

remexre 4y ago
- Integer promotion -- Nope, you need to explicitly cast; integer _literals_ get their type inferred, though. - Implicit casts It has the following coercions: + Subtyping, which is based on lifetimes, not inheritance -- e.g. I can use a global array somewhere an array with a shorter lifetime is required + unique references to shared references, unique references to mut pointers, shared references to const pointers, mut pointers to const pointers &mut ---> & | | v v *mut ---> *const + "deref coercion" -- basically, if you have a smart pointer (e.g. a reference counting one), you can get a reference out of it + "unsizing coercions" -- if you have some pointer type that points to e.g. an array of known size, and you want to change it to a (bounds-checked!) pointer to an array of unknown size (a slice, in Rust parlance), that coercion occurs + function types to function pointer types + the ! type to any other type -- there are no values of the ! type, so this is sound (it's the type that e.g. exit() returns) - loop keywords -- it's just for and while, not even do-while - switch -- It has real ML-style pattern-matching, with extra goodies for pattern-matching on arrays more easily. This doesn't have the fallthrough problems of C, and is more expressive to boot. - enum -- Again, the real ML-style design. Typesafe, and _far_ more expressive. - _Generic -- Another ML-family design :) This time via traits, which are similar to typeclasses in languages that have those instead. Think, "interfaces, but don't require a vtable (unless the programmer requests one)" - typeof -- Nope, though there's (ML-family-style again!) type inference, so the cases where it'd be necessary in e.g. C macros just aren't a problem. - No explicit number of bits -- the builtin types are u8, i32, f64, etc. -- the only ambiguously-sized integers are isize/usize, which I believe are specified to be the same size as size_t; I don't know that there's a pointer-sized integer type for platforms with larger pointers than size_t's (e.g. ARM Morello and other CHERI CPUs) Which language(s) do you like more for writing this kind of systems program?
- sylware 4y ago
  come on... with all that neither rust nor C. It makes me want to send all that to hell and write assembly.

metadat 4y ago

Note: In this context, DRM stands for "Direct Rendering Manager" [driver]. It threw me for a loop at first, "What on earth does the Linux Kernel and Rust have to do with Digital Rights Management / copy protection!?"