mirror of https://github.com/rust-lang/rust
61 lines
1.3 KiB
Rust
61 lines
1.3 KiB
Rust
//@ run-pass
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#![allow(unreachable_code)]
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#![allow(unused_labels)]
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// Test that labels injected by macros do not break hygiene.
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// Issue #24278: The label/lifetime shadowing checker from #24162
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// conservatively ignores hygiene, and thus issues warnings that are
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// both true- and false-positives for this test.
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macro_rules! loop_x {
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($e: expr) => {
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// $e shouldn't be able to interact with this 'x
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'x: loop {
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$e
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}
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};
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}
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macro_rules! run_once {
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($e: expr) => {
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// ditto
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'x: for _ in 0..1 {
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$e
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}
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};
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}
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macro_rules! while_x {
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($e: expr) => {
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// ditto
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'x: while 1 + 1 == 2 {
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$e
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}
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};
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}
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pub fn main() {
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'x: for _ in 0..1 {
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// this 'x should refer to the outer loop, lexically
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loop_x!(break 'x);
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panic!("break doesn't act hygienically inside for loop");
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}
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'x: loop {
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// ditto
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loop_x!(break 'x);
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panic!("break doesn't act hygienically inside infinite loop");
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}
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'x: while 1 + 1 == 2 {
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while_x!(break 'x);
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panic!("break doesn't act hygienically inside infinite while loop");
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}
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'x: for _ in 0..1 {
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// ditto
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run_once!(continue 'x);
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panic!("continue doesn't act hygienically inside for loop");
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}
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}
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