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|
// run-pass
#![allow(non_upper_case_globals)]
// Issue 23611: this test is ensuring that, for an instance `X` of the
// enum `E`, if you swap in a different variant during the execution
// of the `<E as Drop>::drop`, then the appropriate substructure will
// be torn down after the `<E as Drop>::drop` method returns.
use std::cell::RefCell;
use std::mem;
use self::d::D;
pub fn main() {
let log = RefCell::new(vec![]);
d::println("created empty log");
test(&log);
// println!("log: {:?}", &log.borrow()[..]);
assert_eq!(
&log.borrow()[..],
[
// created empty log
// +-- Make D(test_1, 10000000)
// | +-- Make D(g_b_5, 50000001)
// | | in g_B(b2b0) from E::drop, b=b4b0
// | +-- Drop D(g_b_5, 50000001)
50000001,
// |
// | +-- Make D(drop_6, 60000002)
// | | +-- Make D(g_b_5, 50000003)
// | | | in g_B(b2b0) from E::drop, b=b4b1
// | | +-- Drop D(g_b_5, 50000003)
50000003,
// | |
// | | +-- Make D(GaspB::drop_3, 30000004)
// | | | +-- Make D(g_b_5, 50000005)
// | | | | in g_B(b4b2) from GaspB::drop
// | | | +-- Drop D(g_b_5, 50000005)
50000005,
// | | |
// | | +-- Drop D(GaspB::drop_3, 30000004)
30000004,
// | |
// +-- Drop D(test_1, 10000000)
10000000,
// |
// +-- Make D(GaspA::drop_2, 20000006)
// | | +-- Make D(f_a_4, 40000007)
// | | | in f_A(a3a0) from GaspA::drop
// | | +-- Drop D(f_a_4, 40000007)
40000007,
// | |
// +-- Drop D(GaspA::drop_2, 20000006)
20000006,
// |
// +-- Drop D(drop_6, 60000002)
60000002
//
]);
// For reference purposes, the old (incorrect) behavior would produce the following
// output, which you can compare to the above:
//
// created empty log
// +-- Make D(test_1, 10000000)
// | +-- Make D(g_b_5, 50000001)
// | | in g_B(b2b0) from E::drop, b=b4b0
// | +-- Drop D(g_b_5, 50000001)
// |
// | +-- Make D(drop_6, 60000002)
// | | +-- Make D(g_b_5, 50000003)
// | | | in g_B(b2b0) from E::drop, b=b4b1
// | | +-- Drop D(g_b_5, 50000003)
// | |
// | | +-- Make D(GaspB::drop_3, 30000004)
// | | | +-- Make D(g_b_5, 50000005)
// | | | | in g_B(b4b2) from GaspB::drop
// | | | +-- Drop D(g_b_5, 50000005)
// | | |
// | | +-- Drop D(GaspB::drop_3, 30000004)
// | |
// +-- Drop D(test_1, 10000000)
// |
// +-- Make D(GaspB::drop_3, 30000006)
// | | +-- Make D(f_a_4, 40000007)
// | | | in f_A(a3a0) from GaspB::drop
// | | +-- Drop D(f_a_4, 40000007)
// | |
// +-- Drop D(GaspB::drop_3, 30000006)
// |
// +-- Drop D(drop_6, 60000002)
// Note that this calls f_A from GaspB::drop (and thus creates a D
// with a uid incorporating the origin of GaspB's drop that
// surrounds the f_A invocation), but the code as written only
// ever hands f_A off to instances of GaspA, and thus one should
// be able to prove the invariant that f_A is *only* invoked from
// from an instance of GaspA (either via the GaspA drop
// implementation or the E drop implementaton). Yet the old (bad)
// behavior allowed a call to f_A to leak in while we are tearing
// down a value of type GaspB.
}
fn test<'a>(log: d::Log<'a>) {
let _e = E::B(GaspB(g_b, 0xB4B0, log, D::new("test", 1, log)), true);
}
struct GaspA<'a>(for <'b> fn(u32, &'b str, d::Log<'a>), u32, d::Log<'a>, d::D<'a>);
struct GaspB<'a>(for <'b> fn(u32, &'b str, d::Log<'a>), u32, d::Log<'a>, d::D<'a>);
impl<'a> Drop for GaspA<'a> {
fn drop(&mut self) {
let _d = d::D::new("GaspA::drop", 2, self.2);
(self.0)(self.1, "GaspA::drop", self.2);
}
}
impl<'a> Drop for GaspB<'a> {
fn drop(&mut self) {
let _d = d::D::new("GaspB::drop", 3, self.2);
(self.0)(self.1, "GaspB::drop", self.2);
}
}
enum E<'a> {
A(GaspA<'a>, bool), B(GaspB<'a>, bool),
}
fn f_a(x: u32, ctxt: &str, log: d::Log) {
let _d = d::D::new("f_a", 4, log);
d::println(&format!("in f_A({:x}) from {}", x, ctxt));
}
fn g_b(y: u32, ctxt: &str, log: d::Log) {
let _d = d::D::new("g_b", 5, log);
d::println(&format!("in g_B({:x}) from {}", y, ctxt));
}
impl<'a> Drop for E<'a> {
fn drop(&mut self) {
let (do_drop, log) = match *self {
E::A(GaspA(ref f, ref mut val_a, log, ref _d_a), ref mut do_drop) => {
f(0xA1A0, &format!("E::drop, a={:x}", val_a), log);
*val_a += 1;
// swap in do_drop := false to avoid infinite dtor regress
(mem::replace(do_drop, false), log)
}
E::B(GaspB(ref g, ref mut val_b, log, ref _d_b), ref mut do_drop) => {
g(0xB2B0, &format!("E::drop, b={:x}", val_b), log);
*val_b += 1;
// swap in do_drop := false to avoid infinite dtor regress
(mem::replace(do_drop, false), log)
}
};
#[allow(unused_must_use)]
if do_drop {
mem::replace(self, E::A(GaspA(f_a, 0xA3A0, log, D::new("drop", 6, log)), true));
}
}
}
// This module provides simultaneous printouts of the dynamic extents
// of all of the D values, in addition to logging the order that each
// is dropped.
//
// This code is similar to a support code module embedded within
// test/run-pass/issue-123338-ensure-param-drop-order.rs; however,
// that (slightly simpler) code only identifies objects in the log via
// (creation) time-stamps; this incorporates both timestamping and the
// point of origin within the source code into the unique ID (uid).
const PREF_INDENT: u32 = 20;
pub mod d {
#![allow(unused_parens)]
use std::fmt;
use std::mem;
use std::cell::RefCell;
static mut counter: u16 = 0;
static mut trails: u64 = 0;
pub type Log<'a> = &'a RefCell<Vec<u32>>;
pub fn current_width() -> u32 {
unsafe { max_width() - trails.leading_zeros() }
}
pub fn max_width() -> u32 {
unsafe {
(mem::size_of_val(&trails)*8) as u32
}
}
pub fn indent_println(my_trails: u32, s: &str) {
let mut indent: String = String::new();
for i in 0..my_trails {
unsafe {
if trails & (1 << i) != 0 {
indent = indent + "| ";
} else {
indent = indent + " ";
}
}
}
println!("{}{}", indent, s);
}
pub fn println(s: &str) {
indent_println(super::PREF_INDENT, s);
}
fn first_avail() -> u32 {
unsafe {
for i in 0..64 {
if trails & (1 << i) == 0 {
return i;
}
}
}
panic!("exhausted trails");
}
pub struct D<'a> {
name: &'static str, i: u8, uid: u32, trail: u32, log: Log<'a>
}
impl<'a> fmt::Display for D<'a> {
fn fmt(&self, w: &mut fmt::Formatter) -> fmt::Result {
write!(w, "D({}_{}, {})", self.name, self.i, self.uid)
}
}
impl<'a> D<'a> {
pub fn new(name: &'static str, i: u8, log: Log<'a>) -> D<'a> {
unsafe {
let trail = first_avail();
let ctr = ((i as u32) * 10_000_000) + (counter as u32);
counter += 1;
trails |= (1 << trail);
let ret = D {
name: name, i: i, log: log, uid: ctr, trail: trail
};
indent_println(trail, &format!("+-- Make {}", ret));
ret
}
}
}
impl<'a> Drop for D<'a> {
fn drop(&mut self) {
unsafe { trails &= !(1 << self.trail); };
self.log.borrow_mut().push(self.uid);
indent_println(self.trail, &format!("+-- Drop {}", self));
indent_println(::PREF_INDENT, "");
}
}
}
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