rust/src/test/run-pass/cleanup-rvalue-temp-during-incomplete-alloc.rs
Niko Matsakis 419ac4a1b8 Issue #3511 - Rationalize temporary lifetimes.
Major changes:

- Define temporary scopes in a syntax-based way that basically defaults
  to the innermost statement or conditional block, except for in
  a `let` initializer, where we default to the innermost block. Rules
  are documented in the code, but not in the manual (yet).
  See new test run-pass/cleanup-value-scopes.rs for examples.
- Refactors Datum to better define cleanup roles.
- Refactor cleanup scopes to not be tied to basic blocks, permitting
  us to have a very large number of scopes (one per AST node).
- Introduce nascent documentation in trans/doc.rs covering datums and
  cleanup in a more comprehensive way.
2014-01-15 18:34:38 -05:00

40 lines
935 B
Rust

// Test cleanup of rvalue temporary that occurs while `~` construction
// is in progress. This scenario revealed a rather terrible bug. The
// ingredients are:
//
// 1. Partial cleanup of `~` is in scope,
// 2. cleanup of return value from `get_bar()` is in scope,
// 3. do_it() fails.
//
// This led to a bug because `the top-most frame that was to be
// cleaned (which happens to be the partial cleanup of `~`) required
// multiple basic blocks, which led to us dropping part of the cleanup
// from the top-most frame.
//
// It's unclear how likely such a bug is to recur, but it seems like a
// scenario worth testing.
use std::task;
enum Conzabble {
Bickwick(Foo)
}
struct Foo { field: ~uint }
fn do_it(x: &[uint]) -> Foo {
fail!()
}
fn get_bar(x: uint) -> ~[uint] { ~[x * 2] }
pub fn fails() {
let x = 2;
let mut y = ~[];
y.push(~Bickwick(do_it(get_bar(x))));
}
pub fn main() {
task::try(fails);
}