diff --git a/src/librustc_mir/build/mod.rs b/src/librustc_mir/build/mod.rs index a01f8940a948a..a123f97efa832 100644 --- a/src/librustc_mir/build/mod.rs +++ b/src/librustc_mir/build/mod.rs @@ -915,6 +915,13 @@ impl<'a, 'gcx, 'tcx> Builder<'a, 'gcx, 'tcx> { let place = Place::Local(local); let &ArgInfo(ty, opt_ty_info, pattern, ref self_binding) = arg_info; + // Make sure we drop (parts of) the argument even when not matched on. + self.schedule_drop( + pattern.as_ref().map_or(ast_body.span, |pat| pat.span), + argument_scope, &place, ty, + DropKind::Value { cached_block: CachedBlock::default() }, + ); + if let Some(pattern) = pattern { let pattern = self.hir.pattern_from_hir(pattern); let span = pattern.span; @@ -946,13 +953,6 @@ impl<'a, 'gcx, 'tcx> Builder<'a, 'gcx, 'tcx> { } } } - - // Make sure we drop (parts of) the argument even when not matched on. - self.schedule_drop( - pattern.as_ref().map_or(ast_body.span, |pat| pat.span), - argument_scope, &place, ty, - DropKind::Value { cached_block: CachedBlock::default() }, - ); } // Enter the argument pattern bindings source scope, if it exists. diff --git a/src/test/run-pass/binding/fn-arg-incomplete-pattern-drop-order.rs b/src/test/run-pass/binding/fn-arg-incomplete-pattern-drop-order.rs new file mode 100644 index 0000000000000..41e0750000146 --- /dev/null +++ b/src/test/run-pass/binding/fn-arg-incomplete-pattern-drop-order.rs @@ -0,0 +1,54 @@ +// Check that partially moved from function parameters are dropped after the +// named bindings that move from them. + +use std::{panic, cell::RefCell}; + +struct LogDrop<'a>(i32, Context<'a>); + +#[derive(Copy, Clone)] +struct Context<'a> { + panic_on: i32, + drops: &'a RefCell>, +} + +impl<'a> Context<'a> { + fn record_drop(self, index: i32) { + self.drops.borrow_mut().push(index); + if index == self.panic_on { + panic!(); + } + } +} + +impl<'a> Drop for LogDrop<'a> { + fn drop(&mut self) { + self.1.record_drop(self.0); + } +} + +fn foo((_x, _): (LogDrop, LogDrop), (_, _y): (LogDrop, LogDrop)) {} + +fn test_drop_order(panic_on: i32) { + let context = Context { + panic_on, + drops: &RefCell::new(Vec::new()), + }; + let one = LogDrop(1, context); + let two = LogDrop(2, context); + let three = LogDrop(3, context); + let four = LogDrop(4, context); + + let res = panic::catch_unwind(panic::AssertUnwindSafe(|| { + foo((three, four), (two, one)); + })); + if panic_on == 0 { + assert!(res.is_ok(), "should not have panicked"); + } else { + assert!(res.is_err(), "should have panicked"); + } + assert_eq!(*context.drops.borrow(), [1, 2, 3, 4], "incorrect drop order"); +} + +fn main() { + (0..=4).for_each(test_drop_order); +}