mirror of https://github.com/rust-lang/rust
22 lines
763 B
Rust
22 lines
763 B
Rust
//@ compile-flags: -C no-prepopulate-passes -Zbranch-protection=bti
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//@ assembly-output: emit-asm
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//@ needs-asm-support
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//@ only-aarch64
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#![crate_type = "lib"]
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#![feature(naked_functions)]
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use std::arch::asm;
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// The problem at hand: Rust has adopted a fairly strict meaning for "naked functions",
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// meaning "no prologue whatsoever, no, really, not one instruction."
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// Unfortunately, aarch64's "branch target identification" works via hints at landing sites.
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// LLVM implements this via making sure of that, even for functions with the naked attribute.
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// So, we must emit an appropriate instruction instead!
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#[no_mangle]
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#[naked]
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pub unsafe extern "C" fn _hlt() -> ! {
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// CHECK-NOT: hint #34
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// CHECK: hlt #0x1
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asm!("hlt #1", options(noreturn))
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}
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