bors b583ede652 Auto merge of #99767 - LeSeulArtichaut:stable-target-feature-11, r=estebank ... Stabilize `#![feature(target_feature_11)]` ## Stabilization report ### Summary Allows for safe functions to be marked with `#[target_feature]` attributes. Functions marked with `#[target_feature]` are generally considered as unsafe functions: they are unsafe to call, cannot be assigned to safe function pointers, and don't implement the `Fn*` traits. However, calling them from other `#[target_feature]` functions with a superset of features is safe. ```rust // Demonstration function #[target_feature(enable = "avx2")] fn avx2() {} fn foo() { // Calling `avx2` here is unsafe, as we must ensure // that AVX is available first. unsafe { avx2(); } } #[target_feature(enable = "avx2")] fn bar() { // Calling `avx2` here is safe. avx2(); } ``` ### Test cases Tests for this feature can be found in [`src/test/ui/rfcs/rfc-2396-target_feature-11/`](b67ba9ba20/src/test/ui/rfcs/rfc-2396-target_feature-11/). ### Edge cases - https://github.com/rust-lang/rust/issues/73631 Closures defined inside functions marked with `#[target_feature]` inherit the target features of their parent function. They can still be assigned to safe function pointers and implement the appropriate `Fn*` traits. ```rust #[target_feature(enable = "avx2")] fn qux() { let my_closure = || avx2(); // this call to `avx2` is safe let f: fn() = my_closure; } ``` This means that in order to call a function with `#[target_feature]`, you must show that the target-feature is available while the function executes *and* for as long as whatever may escape from that function lives. ### Documentation - Reference: https://github.com/rust-lang/reference/pull/1181 --- cc tracking issue #69098 r? `@ghost`		2023-02-28 01:14:56 +00:00
..
alloc	Disambiguate comments	2023-02-26 03:13:56 +01:00
backtrace@07872f28cd
core	Auto merge of #99767 - LeSeulArtichaut:stable-target-feature-11, r=estebank	2023-02-28 01:14:56 +00:00
panic_abort
panic_unwind
portable-simd
proc_macro	Auto merge of #105671 - lukas-code:depreciate-char, r=scottmcm	2023-02-12 11:09:06 +00:00
profiler_builtins
rtstartup
rustc-std-workspace-alloc
rustc-std-workspace-core
rustc-std-workspace-std
std	Rollup merge of #107110 - strega-nil:mbtwc-wctmb, r=ChrisDenton	2023-02-27 18:48:48 +01:00
stdarch@a0c30f3e3c
test	test: drop unused deps	2023-02-24 20:45:00 +03:00
unwind