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| 1 | +// Copyright 2015 The Rust Project Developers. See the COPYRIGHT |
| 2 | +// file at the top-level directory of this distribution and at |
| 3 | +// http://rust-lang.org/COPYRIGHT. |
| 4 | +// |
| 5 | +// Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or |
| 6 | +// http://www.apache.org/licenses/LICENSE-2.0> or the MIT license |
| 7 | +// <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your |
| 8 | +// option. This file may not be copied, modified, or distributed |
| 9 | +// except according to those terms. |
| 10 | + |
| 11 | +// This test is ensuring that parameters are indeed dropped after |
| 12 | +// temporaries in a fn body. |
| 13 | + |
| 14 | +use std::cell::RefCell; |
| 15 | + |
| 16 | +use self::d::D; |
| 17 | + |
| 18 | +pub fn main() { |
| 19 | + let log = RefCell::new(vec![]); |
| 20 | + d::println(&format!("created empty log")); |
| 21 | + test(&log); |
| 22 | + |
| 23 | + assert_eq!(&log.borrow()[..], |
| 24 | + [ |
| 25 | + // created empty log |
| 26 | + // +-- Make D(da_0, 0) |
| 27 | + // | +-- Make D(de_1, 1) |
| 28 | + // | | calling foo |
| 29 | + // | | entered foo |
| 30 | + // | | +-- Make D(de_2, 2) |
| 31 | + // | | | +-- Make D(da_1, 3) |
| 32 | + // | | | | +-- Make D(de_3, 4) |
| 33 | + // | | | | | +-- Make D(de_4, 5) |
| 34 | + 3, // | | | +-- Drop D(da_1, 3) |
| 35 | + // | | | | | |
| 36 | + 4, // | | | +-- Drop D(de_3, 4) |
| 37 | + // | | | | |
| 38 | + // | | | | eval tail of foo |
| 39 | + // | | | +-- Make D(de_5, 6) |
| 40 | + // | | | | +-- Make D(de_6, 7) |
| 41 | + 6, // | | | +-- Drop D(de_5, 6) |
| 42 | + // | | | | | |
| 43 | + 5, // | | | | +-- Drop D(de_4, 5) |
| 44 | + // | | | | |
| 45 | + 2, // | | +-- Drop D(de_2, 2) |
| 46 | + // | | | |
| 47 | + 1, // | +-- Drop D(de_1, 1) |
| 48 | + // | | |
| 49 | + 0, // +-- Drop D(da_0, 0) |
| 50 | + // | |
| 51 | + // | result D(de_6, 7) |
| 52 | + 7 // +-- Drop D(de_6, 7) |
| 53 | + |
| 54 | + ]); |
| 55 | +} |
| 56 | + |
| 57 | +fn test<'a>(log: d::Log<'a>) { |
| 58 | + let da = D::new("da", 0, log); |
| 59 | + let de = D::new("de", 1, log); |
| 60 | + d::println(&format!("calling foo")); |
| 61 | + let result = foo(da, de); |
| 62 | + d::println(&format!("result {}", result)); |
| 63 | +} |
| 64 | + |
| 65 | +fn foo<'a>(da0: D<'a>, de1: D<'a>) -> D<'a> { |
| 66 | + d::println(&format!("entered foo")); |
| 67 | + let de2 = de1.incr(); // creates D(de_2, 2) |
| 68 | + let de4 = { |
| 69 | + let _da1 = da0.incr(); // creates D(da_1, 3) |
| 70 | + de2.incr().incr() // creates D(de_3, 4) and D(de_4, 5) |
| 71 | + }; |
| 72 | + d::println(&format!("eval tail of foo")); |
| 73 | + de4.incr().incr() // creates D(de_5, 6) and D(de_6, 7) |
| 74 | +} |
| 75 | + |
| 76 | +// This module provides simultaneous printouts of the dynamic extents |
| 77 | +// of all of the D values, in addition to logging the order that each |
| 78 | +// is dropped. |
| 79 | + |
| 80 | +const PREF_INDENT: u32 = 16; |
| 81 | + |
| 82 | +pub mod d { |
| 83 | + #![allow(unused_parens)] |
| 84 | + use std::fmt; |
| 85 | + use std::mem; |
| 86 | + use std::cell::RefCell; |
| 87 | + |
| 88 | + static mut counter: u32 = 0; |
| 89 | + static mut trails: u64 = 0; |
| 90 | + |
| 91 | + pub type Log<'a> = &'a RefCell<Vec<u32>>; |
| 92 | + |
| 93 | + pub fn current_width() -> u32 { |
| 94 | + unsafe { max_width() - trails.leading_zeros() } |
| 95 | + } |
| 96 | + |
| 97 | + pub fn max_width() -> u32 { |
| 98 | + unsafe { |
| 99 | + (mem::size_of_val(&trails)*8) as u32 |
| 100 | + } |
| 101 | + } |
| 102 | + |
| 103 | + pub fn indent_println(my_trails: u32, s: &str) { |
| 104 | + let mut indent: String = String::new(); |
| 105 | + for i in 0..my_trails { |
| 106 | + unsafe { |
| 107 | + if trails & (1 << i) != 0 { |
| 108 | + indent = indent + "| "; |
| 109 | + } else { |
| 110 | + indent = indent + " "; |
| 111 | + } |
| 112 | + } |
| 113 | + } |
| 114 | + println!("{}{}", indent, s); |
| 115 | + } |
| 116 | + |
| 117 | + pub fn println(s: &str) { |
| 118 | + indent_println(super::PREF_INDENT, s); |
| 119 | + } |
| 120 | + |
| 121 | + fn first_avail() -> u32 { |
| 122 | + unsafe { |
| 123 | + for i in 0..64 { |
| 124 | + if trails & (1 << i) == 0 { |
| 125 | + return i; |
| 126 | + } |
| 127 | + } |
| 128 | + } |
| 129 | + panic!("exhausted trails"); |
| 130 | + } |
| 131 | + |
| 132 | + pub struct D<'a> { |
| 133 | + name: &'static str, i: u32, uid: u32, trail: u32, log: Log<'a> |
| 134 | + } |
| 135 | + |
| 136 | + impl<'a> fmt::Display for D<'a> { |
| 137 | + fn fmt(&self, w: &mut fmt::Formatter) -> fmt::Result { |
| 138 | + write!(w, "D({}_{}, {})", self.name, self.i, self.uid) |
| 139 | + } |
| 140 | + } |
| 141 | + |
| 142 | + impl<'a> D<'a> { |
| 143 | + pub fn new(name: &'static str, i: u32, log: Log<'a>) -> D<'a> { |
| 144 | + unsafe { |
| 145 | + let trail = first_avail(); |
| 146 | + let ctr = counter; |
| 147 | + counter += 1; |
| 148 | + trails |= (1 << trail); |
| 149 | + let ret = D { |
| 150 | + name: name, i: i, log: log, uid: ctr, trail: trail |
| 151 | + }; |
| 152 | + indent_println(trail, &format!("+-- Make {}", ret)); |
| 153 | + ret |
| 154 | + } |
| 155 | + } |
| 156 | + pub fn incr(&self) -> D<'a> { |
| 157 | + D::new(self.name, self.i + 1, self.log) |
| 158 | + } |
| 159 | + } |
| 160 | + |
| 161 | + impl<'a> Drop for D<'a> { |
| 162 | + fn drop(&mut self) { |
| 163 | + unsafe { trails &= !(1 << self.trail); }; |
| 164 | + self.log.borrow_mut().push(self.uid); |
| 165 | + indent_println(self.trail, &format!("+-- Drop {}", self)); |
| 166 | + indent_println(::PREF_INDENT, ""); |
| 167 | + } |
| 168 | + } |
| 169 | +} |
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