mirror of https://github.com/rust-lang/rust
75 lines
1.7 KiB
Rust
75 lines
1.7 KiB
Rust
// Issue #29793, big regression test: do not let borrows of
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// parameters to ever be returned (expanded with exploration of
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// variations).
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//
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// This is the version of the test that actually exposed unsound
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// behavior (because the improperly accepted closure was actually
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// able to be invoked).
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struct WrapA<F>(Option<F>);
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impl<F> WrapA<F> {
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fn new() -> WrapA<F> {
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WrapA(None)
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}
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fn set(mut self, f: F) -> Self {
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self.0 = Some(f);
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self
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}
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}
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struct WrapB<F>(Option<F>);
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impl<F> WrapB<F> {
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fn new() -> WrapB<F> {
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WrapB(None)
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}
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fn set(mut self, f: F) -> Self {
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self.0 = Some(f);
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self
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}
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}
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trait DoStuff : Sized {
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fn handle(self);
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}
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impl<F, T> DoStuff for WrapA<F>
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where F: FnMut(usize, usize) -> T, T: DoStuff {
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fn handle(mut self) {
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if let Some(ref mut f) = self.0 {
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let x = f(1, 2);
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let _foo = [0usize; 16];
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x.handle();
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}
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}
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}
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impl<F> DoStuff for WrapB<F> where F: FnMut(bool) -> usize {
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fn handle(mut self) {
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if let Some(ref mut f) = self.0 {
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println!("{}", f(true));
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}
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}
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}
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impl<F, T> WrapA<F>
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where F: FnMut(usize, usize) -> T, T: DoStuff {
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fn handle_ref(&mut self) {
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if let Some(ref mut f) = self.0 {
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let x = f(1, 2);
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}
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}
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}
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fn main() {
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let mut w = WrapA::new().set(|x: usize, y: usize| {
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WrapB::new().set(|t: bool| if t { x } else { y }) // (separate errors for `x` vs `y`)
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//~^ ERROR closure may outlive the current function
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//~| ERROR closure may outlive the current function
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});
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w.handle(); // This works
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// w.handle_ref(); // This doesn't
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}
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