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| Original file line number | Diff line number | Diff line change |
|---|---|---|
| @@ -0,0 +1,51 @@ | ||
| // compile-flags: -O | ||
| // only-x86_64 | ||
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| #![crate_type = "rlib"] | ||
| #![feature(asm_goto)] | ||
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| use std::arch::asm; | ||
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| #[no_mangle] | ||
| pub extern "C" fn panicky() {} | ||
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| struct Foo; | ||
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| impl Drop for Foo { | ||
| fn drop(&mut self) { | ||
| println!(); | ||
| } | ||
| } | ||
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| // CHECK-LABEL: @asm_goto | ||
| #[no_mangle] | ||
| pub unsafe fn asm_goto() { | ||
| // CHECK: callbr void asm sideeffect alignstack inteldialect " | ||
| // CHECK-NEXT: to label %[[FALLTHROUGHBB:[a-b0-9]+]] [label %[[JUMPBB:[a-b0-9]+]]] | ||
| asm!("jmp {}", label {}); | ||
| } | ||
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| // CHECK-LABEL: @asm_goto_with_outputs | ||
| #[no_mangle] | ||
| pub unsafe fn asm_goto_with_outputs() -> u64 { | ||
| let out: u64; | ||
| // CHECK: [[RES:%[0-9]+]] = callbr i64 asm sideeffect alignstack inteldialect " | ||
| // CHECK-NEXT: to label %[[FALLTHROUGHBB:[a-b0-9]+]] [label %[[JUMPBB:[a-b0-9]+]]] | ||
| asm!("{} /* {} */", out(reg) out, label { return 1; }); | ||
| // CHECK: [[JUMPBB]]: | ||
| // CHECK-NEXT: [[RET:%.+]] = phi i64 [ [[RES]], %[[FALLTHROUGHBB]] ], [ 1, %start ] | ||
| // CHECK-NEXT: ret i64 [[RET]] | ||
| out | ||
| } | ||
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| // CHECK-LABEL: @asm_goto_noreturn | ||
| #[no_mangle] | ||
| pub unsafe fn asm_goto_noreturn() -> u64 { | ||
| let out: u64; | ||
| // CHECK: callbr void asm sideeffect alignstack inteldialect " | ||
| // CHECK-NEXT: to label %unreachable [label %[[JUMPBB:[a-b0-9]+]]] | ||
| asm!("jmp {}", label { return 1; }, options(noreturn)); | ||
| // CHECK: [[JUMPBB]]: | ||
| // CHECK-NEXT: ret i64 1 | ||
| out | ||
| } |
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| Original file line number | Diff line number | Diff line change |
|---|---|---|
| @@ -0,0 +1,23 @@ | ||
| warning: unreachable statement | ||
| --> $DIR/goto.rs:99:9 | ||
| | | ||
| LL | / asm!( | ||
| LL | | "jmp {}", | ||
| LL | | label { | ||
| LL | | return; | ||
| LL | | }, | ||
| LL | | options(noreturn) | ||
| LL | | ); | ||
| | |_________- any code following this expression is unreachable | ||
| LL | unreachable!(); | ||
| | ^^^^^^^^^^^^^^ unreachable statement | ||
| | | ||
| note: the lint level is defined here | ||
| --> $DIR/goto.rs:89:8 | ||
| | | ||
| LL | #[warn(unreachable_code)] | ||
| | ^^^^^^^^^^^^^^^^ | ||
| = note: this warning originates in the macro `unreachable` (in Nightly builds, run with -Z macro-backtrace for more info) | ||
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| warning: 1 warning emitted | ||
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| Original file line number | Diff line number | Diff line change |
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| @@ -0,0 +1,111 @@ | ||
| // only-x86_64 | ||
| // run-pass | ||
| // needs-asm-support | ||
| // revisions: mirunsafeck thirunsafeck | ||
| // [thirunsafeck]compile-flags: -Z thir-unsafeck | ||
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| #![deny(unreachable_code)] | ||
| #![feature(asm_goto)] | ||
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| use std::arch::asm; | ||
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| fn goto_fallthough() { | ||
| unsafe { | ||
| asm!( | ||
| "/* {} */", | ||
| label { | ||
| unreachable!(); | ||
| } | ||
| ) | ||
| } | ||
| } | ||
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| fn goto_jump() { | ||
| unsafe { | ||
| let mut value = false; | ||
| asm!( | ||
| "jmp {}", | ||
| label { | ||
| value = true; | ||
| } | ||
| ); | ||
| assert!(value); | ||
| } | ||
| } | ||
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| // asm goto with outputs cause miscompilation in LLVM. UB can be triggered | ||
| // when outputs are used inside the label block when optimisation is enabled. | ||
| // See: https://github.com/llvm/llvm-project/issues/74483 | ||
| /* | ||
| fn goto_out_fallthrough() { | ||
| unsafe { | ||
| let mut out: usize; | ||
| asm!( | ||
| "lea {}, [{} + 1]", | ||
| "/* {} */", | ||
| out(reg) out, | ||
| in(reg) 0x12345678usize, | ||
| label { | ||
| unreachable!(); | ||
| } | ||
| ); | ||
| assert_eq!(out, 0x12345679); | ||
| } | ||
| } | ||
| fn goto_out_jump() { | ||
| unsafe { | ||
| let mut value = false; | ||
| let mut out: usize; | ||
| asm!( | ||
| "lea {}, [{} + 1]", | ||
| "jmp {}", | ||
| out(reg) out, | ||
| in(reg) 0x12345678usize, | ||
| label { | ||
| value = true; | ||
| assert_eq!(out, 0x12345679); | ||
| } | ||
| ); | ||
| assert!(value); | ||
| } | ||
| } | ||
| */ | ||
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| fn goto_noreturn() { | ||
| unsafe { | ||
| let a; | ||
| asm!( | ||
| "jmp {}", | ||
| label { | ||
| a = 1; | ||
| }, | ||
| options(noreturn) | ||
| ); | ||
| assert_eq!(a, 1); | ||
| } | ||
| } | ||
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| #[warn(unreachable_code)] | ||
| fn goto_noreturn_diverge() { | ||
| unsafe { | ||
| asm!( | ||
| "jmp {}", | ||
| label { | ||
| return; | ||
| }, | ||
| options(noreturn) | ||
| ); | ||
| unreachable!(); | ||
| //~^ WARN unreachable statement | ||
| } | ||
| } | ||
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| fn main() { | ||
| goto_fallthough(); | ||
| goto_jump(); | ||
| // goto_out_fallthrough(); | ||
| // goto_out_jump(); | ||
| goto_noreturn(); | ||
| goto_noreturn_diverge(); | ||
| } |
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