27 lines
853 B
Rust
27 lines
853 B
Rust
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// compile-flags: -O
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// Once we're done with llvm 14 and earlier, this test can be deleted.
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#![crate_type="lib"]
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use std::mem::MaybeUninit;
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// Boxing a `MaybeUninit` value should not copy junk from the stack
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#[no_mangle]
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pub fn box_uninitialized() -> Box<MaybeUninit<usize>> {
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// CHECK-LABEL: @box_uninitialized
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// CHECK-NOT: store
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// CHECK-NOT: alloca
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// CHECK-NOT: memcpy
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// CHECK-NOT: memset
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Box::new(MaybeUninit::uninit())
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}
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// FIXME: add a test for a bigger box. Currently broken, see
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// https://github.com/rust-lang/rust/issues/58201.
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// Hide the LLVM 15+ `allocalign` attribute in the declaration of __rust_alloc
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// from the CHECK-NOT above. We don't check the attributes here because we can't rely
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// on all of them being set until LLVM 15.
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// CHECK: declare noalias{{.*}} @__rust_alloc(i{{[0-9]+}}, i{{[0-9]+.*}})
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