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author | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-17 12:19:03 +0000 |
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committer | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-17 12:19:03 +0000 |
commit | 64d98f8ee037282c35007b64c2649055c56af1db (patch) | |
tree | 5492bcf97fce41ee1c0b1cc2add283f3e66cdab0 /tests/ui/span/issue28498-reject-passed-to-fn.rs | |
parent | Adding debian version 1.67.1+dfsg1-1. (diff) | |
download | rustc-64d98f8ee037282c35007b64c2649055c56af1db.tar.xz rustc-64d98f8ee037282c35007b64c2649055c56af1db.zip |
Merging upstream version 1.68.2+dfsg1.
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'tests/ui/span/issue28498-reject-passed-to-fn.rs')
-rw-r--r-- | tests/ui/span/issue28498-reject-passed-to-fn.rs | 38 |
1 files changed, 38 insertions, 0 deletions
diff --git a/tests/ui/span/issue28498-reject-passed-to-fn.rs b/tests/ui/span/issue28498-reject-passed-to-fn.rs new file mode 100644 index 000000000..dcd2e9ad4 --- /dev/null +++ b/tests/ui/span/issue28498-reject-passed-to-fn.rs @@ -0,0 +1,38 @@ +// Demonstrate that a type param in negative position causes dropck to reject code +// that might indirectly access previously dropped value. +// +// Compare with run-pass/issue28498-ugeh-with-passed-to-fn.rs + +#[derive(Debug)] +struct ScribbleOnDrop(String); + +impl Drop for ScribbleOnDrop { + fn drop(&mut self) { + self.0 = format!("DROPPED"); + } +} + +struct Foo<T>(u32, T, Box<for <'r> fn(&'r T) -> String>); + +impl<T> Drop for Foo<T> { + fn drop(&mut self) { + // Use of `may_dangle` is unsound, because we pass `T` to the callback in `self.2` + // below, and thus potentially read from borrowed data. + println!("Dropping Foo({}, {})", self.0, (self.2)(&self.1)); + } +} + +fn callback(s: & &ScribbleOnDrop) -> String { format!("{:?}", s) } + +fn main() { + let (last_dropped, foo0); + let (foo1, first_dropped); + + last_dropped = ScribbleOnDrop(format!("last")); + first_dropped = ScribbleOnDrop(format!("first")); + foo0 = Foo(0, &last_dropped, Box::new(callback)); // OK + foo1 = Foo(1, &first_dropped, Box::new(callback)); + //~^ ERROR `first_dropped` does not live long enough + + println!("foo0.1: {:?} foo1.1: {:?}", foo0.1, foo1.1); +} |