rust/library
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
..
alloc move strict provenance lints to new feature gate, remove old feature gates 2024-10-21 15:22:17 +01:00
backtrace@230570f2da Try latest backtrace 2024-08-29 12:13:19 -07:00
core move strict provenance lints to new feature gate, remove old feature gates 2024-10-21 15:22:17 +01:00
panic_abort step cfg(bootstrap) 2024-07-28 14:46:29 -04:00
panic_unwind move strict provenance lints to new feature gate, remove old feature gates 2024-10-21 15:22:17 +01:00
portable-simd move strict provenance lints to new feature gate, remove old feature gates 2024-10-21 15:22:17 +01:00
proc_macro move strict provenance lints to new feature gate, remove old feature gates 2024-10-21 15:22:17 +01:00
profiler_builtins Don't skip nonexistent source files 2024-08-27 17:30:42 +10:00
rtstartup Let InstCombine remove Clone shims inside Clone shims 2024-07-25 15:14:42 -04:00
rustc-std-workspace-alloc
rustc-std-workspace-core
rustc-std-workspace-std
std Rollup merge of #130350 - RalfJung:strict-provenance, r=dtolnay 2024-10-21 18:11:19 +02:00
stdarch@c881fe3231 stdarch: Bump stdarch submodule 2024-10-10 10:16:16 +00:00
sysroot Make profiler_builtins an optional dependency of sysroot, not std 2024-10-17 22:08:36 +11:00
test Change a few &Option<T> into Option<&T> 2024-10-08 23:26:29 -04:00
unwind move strict provenance lints to new feature gate, remove old feature gates 2024-10-21 15:22:17 +01:00
windows_targets Win: Add dbghelp to the list of import libraries 2024-09-06 21:21:49 +00:00
Cargo.lock Update compiler-builtins to 0.1.134 2024-10-19 11:47:43 -04:00
Cargo.toml Auto merge of #129063 - the8472:cold-opt-size, r=Amanieu 2024-09-02 00:58:50 +00:00