rust/tests/codegen/ub-checks.rs

29 lines
979 B
Rust

// With -Zub-checks=yes (enabled by default by -Cdebug-assertions=yes) we will produce a runtime
// check that the index to slice::get_unchecked is in-bounds of the slice. That is tested for by
// tests/ui/precondition-checks/out-of-bounds-get-unchecked.rs
//
// This test ensures that such a runtime check is *not* emitted when debug-assertions are enabled,
// but ub-checks are explicitly disabled.
//@ revisions: DEBUG NOCHECKS
//@ [DEBUG] compile-flags:
//@ [NOCHECKS] compile-flags: -Zub-checks=no
//@ compile-flags: -O -Cdebug-assertions=yes
#![crate_type = "lib"]
use std::ops::Range;
// CHECK-LABEL: @slice_get_unchecked(
#[no_mangle]
pub unsafe fn slice_get_unchecked(x: &[i32], i: usize) -> &i32 {
// CHECK: icmp ult
// NOCHECKS: tail call void @llvm.assume
// DEBUG: br i1
// DEBUG: call core::panicking::panic_nounwind
// DEBUG: unreachable
// CHECK: getelementptr inbounds
// CHECK: ret ptr
x.get_unchecked(i)
}