rust/compiler/rustc_codegen_ssa/src
Matthias Krüger 20b1dadf92
Rollup merge of #130350 - RalfJung:strict-provenance, r=dtolnay
stabilize Strict Provenance and Exposed Provenance APIs

Given that [RFC 3559](https://rust-lang.github.io/rfcs/3559-rust-has-provenance.html) has been accepted, t-lang has approved the concept of provenance to exist in the language. So I think it's time that we stabilize the strict provenance and exposed provenance APIs, and discuss provenance explicitly in the docs:
```rust
// core::ptr
pub const fn without_provenance<T>(addr: usize) -> *const T;
pub const fn dangling<T>() -> *const T;
pub const fn without_provenance_mut<T>(addr: usize) -> *mut T;
pub const fn dangling_mut<T>() -> *mut T;
pub fn with_exposed_provenance<T>(addr: usize) -> *const T;
pub fn with_exposed_provenance_mut<T>(addr: usize) -> *mut T;

impl<T: ?Sized> *const T {
    pub fn addr(self) -> usize;
    pub fn expose_provenance(self) -> usize;
    pub fn with_addr(self, addr: usize) -> Self;
    pub fn map_addr(self, f: impl FnOnce(usize) -> usize) -> Self;
}

impl<T: ?Sized> *mut T {
    pub fn addr(self) -> usize;
    pub fn expose_provenance(self) -> usize;
    pub fn with_addr(self, addr: usize) -> Self;
    pub fn map_addr(self, f: impl FnOnce(usize) -> usize) -> Self;
}

impl<T: ?Sized> NonNull<T> {
    pub fn addr(self) -> NonZero<usize>;
    pub fn with_addr(self, addr: NonZero<usize>) -> Self;
    pub fn map_addr(self, f: impl FnOnce(NonZero<usize>) -> NonZero<usize>) -> Self;
}
```

I also did a pass over the docs to adjust them, because this is no longer an "experiment". The `ptr` docs now discuss the concept of provenance in general, and then they go into the two families of APIs for dealing with provenance: Strict Provenance and Exposed Provenance. I removed the discussion of how pointers also have an associated "address space" -- that is not actually tracked in the pointer value, it is tracked in the type, so IMO it just distracts from the core point of provenance. I also adjusted the docs for `with_exposed_provenance` to make it clear that we cannot guarantee much about this function, it's all best-effort.

There are two unstable lints associated with the strict_provenance feature gate; I moved them to a new [strict_provenance_lints](https://github.com/rust-lang/rust/issues/130351) feature since I didn't want this PR to have an even bigger FCP. ;)

`@rust-lang/opsem` Would be great to get some feedback on the docs here. :)
Nominating for `@rust-lang/libs-api.`

Part of https://github.com/rust-lang/rust/issues/95228.

[FCP comment](https://github.com/rust-lang/rust/pull/130350#issuecomment-2395114536)
2024-10-21 18:11:19 +02:00
..
back Rollup merge of #129079 - Zoxc:thinlto_imp_symbols, r=wesleywiser 2024-10-11 15:36:51 +02:00
debuginfo Get rid of const eval_* and try_eval_* helpers 2024-10-19 18:07:35 +00:00
mir stabilize Strict Provenance and Exposed Provenance 2024-10-21 15:05:35 +01:00
traits Auto merge of #130389 - Luv-Ray:LLVMMDNodeInContext2, r=nikic 2024-09-24 12:07:48 +00:00
assert_module_sources.rs Reformat use declarations. 2024-07-29 08:26:52 +10:00
base.rs Allow dropping dyn principal 2024-10-17 20:43:31 +02:00
codegen_attrs.rs Rollup merge of #130308 - davidtwco:tied-target-consolidation, r=wesleywiser 2024-10-10 22:00:45 +02:00
common.rs Clean up formatting. 2024-09-17 16:24:35 +10:00
errors.rs Rollup merge of #130308 - davidtwco:tied-target-consolidation, r=wesleywiser 2024-10-10 22:00:45 +02:00
lib.rs move strict provenance lints to new feature gate, remove old feature gates 2024-10-21 15:22:17 +01:00
meth.rs fix ices on vfe about principal trait 2024-09-23 15:25:52 +08:00
mono_item.rs Reformat using the new identifier sorting from rustfmt 2024-09-22 19:11:29 -04:00
size_of_val.rs fix ices on vfe about principal trait 2024-09-23 15:25:52 +08:00
target_features.rs Reformat using the new identifier sorting from rustfmt 2024-09-22 19:11:29 -04:00