Auto merge of #139845 - Zalathar:rollup-u5u5y1v, r=Zalathar

Rollup of 17 pull requests

Successful merges:

 - #138374 (Enable contracts for const functions)
 - #138380 (ci: add runners for vanilla LLVM 20)
 - #138393 (Allow const patterns of matches to contain pattern types)
 - #139517 (std: sys: process: uefi: Use NULL stdin by default)
 - #139554 (std: add Output::exit_ok)
 - #139660 (compiletest: Add an experimental new executor to replace libtest)
 - #139669 (Overhaul `AssocItem`)
 - #139671 (Proc macro span API redesign: Replace proc_macro::SourceFile by Span::{file, local_file})
 - #139750 (std/thread: Use default stack size from menuconfig for NuttX)
 - #139772 (Remove `hir::Map`)
 - #139785 (Let CStrings be either 1 or 2 byte aligned.)
 - #139789 (do not unnecessarily leak auto traits in item bounds)
 - #139791 (drop global where-bounds before merging candidates)
 - #139798 (normalize: prefer `ParamEnv` over `AliasBound` candidates)
 - #139822 (Fix: Map EOPNOTSUPP to ErrorKind::Unsupported on Unix)
 - #139833 (Fix some HIR pretty-printing problems)
 - #139836 (Basic tests of MPMC receiver cloning)

r? `@ghost`
`@rustbot` modify labels: rollup

1 files changed, 56 insertions, 0 deletions

diff --git a/tests/ui/contracts/contract-const-fn.rs b/tests/ui/contracts/contract-const-fn.rs
new file mode 100644
index 00000000000..733a06ae570
--- /dev/null
+++ b/tests/ui/contracts/contract-const-fn.rs
@@ -0,0 +1,56 @@
+//! Check if we can annotate a constant function with contracts.
+//!
+//! The contract is only checked at runtime, and it will not fail if evaluated statically.
+//! This is an existing limitation due to the existing architecture and the lack of constant
+//! closures.
+//!
+//@ revisions: all_pass runtime_fail_pre runtime_fail_post
+//
+//@ [all_pass] run-pass
+//
+//@ [runtime_fail_pre] run-fail
+//@ [runtime_fail_post] run-fail
+//
+//@ [all_pass] compile-flags: -Zcontract-checks=yes
+//@ [runtime_fail_pre] compile-flags: -Zcontract-checks=yes
+//@ [runtime_fail_post] compile-flags: -Zcontract-checks=yes
+#![feature(contracts)]
+//~^ WARN the feature `contracts` is incomplete and may not be safe to use and/or cause compiler crashes [incomplete_features]
+
+extern crate core;
+use core::contracts::*;
+
+#[requires(x < 100)]
+const fn less_than_100(x: u8) -> u8 {
+    x
+}
+
+// This is wrong on purpose.
+#[ensures(|ret| *ret)]
+const fn always_true(b: bool) -> bool {
+    b
+}
+
+const ZERO: u8 = less_than_100(0);
+// This is no-op because the contract cannot be checked at compilation time.
+const TWO_HUNDRED: u8 = less_than_100(200);
+
+/// Example from <https://github.com/rust-lang/rust/issues/136925>.
+#[ensures(move |ret: &u32| *ret > x)]
+const fn broken_sum(x: u32, y: u32) -> u32 {
+    x + y
+}
+
+fn main() {
+    assert_eq!(ZERO, 0);
+    assert_eq!(TWO_HUNDRED, 200);
+    assert_eq!(broken_sum(0, 1), 1);
+    assert_eq!(always_true(true), true);
+
+    #[cfg(runtime_fail_post)]
+    let _ok = always_true(false);
+
+    // Runtime check should fail.
+    #[cfg(runtime_fail_pre)]
+    let _200 = less_than_100(200);
+}