mirror of https://github.com/rust-lang/rust
42 lines
1.1 KiB
Rust
42 lines
1.1 KiB
Rust
//@ revisions:rpass1 rpass2
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// This test case makes sure re-order the methods in a vtable will
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// trigger recompilation of codegen units that instantiate it.
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//
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// See https://github.com/rust-lang/rust/issues/89598
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trait Foo {
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#[cfg(rpass1)]
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fn method1(&self) -> u32;
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fn method2(&self) -> u32;
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#[cfg(rpass2)]
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fn method1(&self) -> u32;
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}
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impl Foo for u32 {
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fn method1(&self) -> u32 { 17 }
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fn method2(&self) -> u32 { 42 }
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}
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fn main() {
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// Before #89598 was fixed, the vtable allocation would be cached during
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// a MIR optimization pass and then the codegen pass for the main object
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// file would not register a dependency on it (because of the missing
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// dep-tracking).
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//
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// In the rpass2 session, the main object file would not be re-compiled,
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// thus the mod1::foo(x) call would pass in an outdated vtable, while the
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// mod1 object would expect the new, re-ordered vtable, resulting in a
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// call to the wrong method.
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let x: &dyn Foo = &0u32;
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assert_eq!(mod1::foo(x), 17);
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}
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mod mod1 {
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pub(super) fn foo(x: &dyn super::Foo) -> u32 {
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x.method1()
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}
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}
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