diff --git a/src/test/run-pass/dropck_legal_cycles.rs b/src/test/run-pass/dropck_legal_cycles.rs new file mode 100644 index 0000000000000..b4f9b3f945809 --- /dev/null +++ b/src/test/run-pass/dropck_legal_cycles.rs @@ -0,0 +1,759 @@ +// Copyright 2015 The Rust Project Developers. See the COPYRIGHT +// file at the top-level directory of this distribution and at +// http://rust-lang.org/COPYRIGHT. +// +// Licensed under the Apache License, Version 2.0 or the MIT license +// , at your +// option. This file may not be copied, modified, or distributed +// except according to those terms. + +// This test exercises cases where cyclic structure is legal, +// including when the cycles go through data-structures such +// as `Vec` or `TypedArena`. +// +// The intent is to cover as many such cases as possible, ensuring +// that if the compiler did not complain circa Rust 1.x (1.2 as of +// this writing), then it will continue to not complain in the future. +// +// Note that while some of the tests are only exercising using the +// given collection as a "backing store" for a set of nodes that hold +// the actual cycle (and thus the cycle does not go through the +// collection itself in such cases), in general we *do* want to make +// sure to have at least one example exercising a cycle that goes +// through the collection, for every collection type that supports +// this. + +#![feature(vecmap)] + +use std::cell::Cell; +use std::cmp::Ordering; +use std::collections::BinaryHeap; +use std::collections::HashMap; +use std::collections::LinkedList; +use std::collections::VecDeque; +use std::collections::VecMap; +use std::collections::btree_map::BTreeMap; +use std::collections::btree_set::BTreeSet; +use std::hash::{Hash, Hasher}; + +const PRINT: bool = false; + +pub fn main() { + let c_orig = ContextData { + curr_depth: 0, + max_depth: 3, + visited: 0, + max_visits: 1000, + skipped: 0, + curr_mark: 0, + saw_prev_marked: false, + }; + + // Cycle 1: { v[0] -> v[1], v[1] -> v[0] }; + // does not exercise `v` itself + let v: Vec = vec![Named::new("s0"), + Named::new("s1")]; + v[0].next.set(Some(&v[1])); + v[1].next.set(Some(&v[0])); + + let mut c = c_orig.clone(); + c.curr_mark = 10; + assert!(!c.saw_prev_marked); + v[0].for_each_child(&mut c); + assert!(c.saw_prev_marked); + + if PRINT { println!(""); } + + // Cycle 2: { v[0] -> v, v[1] -> v } + let v: V = Named::new("v"); + v.contents[0].set(Some(&v)); + v.contents[1].set(Some(&v)); + + let mut c = c_orig.clone(); + c.curr_mark = 20; + assert!(!c.saw_prev_marked); + v.for_each_child(&mut c); + assert!(c.saw_prev_marked); + + if PRINT { println!(""); } + + // Cycle 3: { hk0 -> hv0, hv0 -> hk0, hk1 -> hv1, hv1 -> hk1 }; + // does not exercise `h` itself + + let mut h: HashMap = HashMap::new(); + h.insert(Named::new("hk0"), Named::new("hv0")); + h.insert(Named::new("hk1"), Named::new("hv1")); + for (key, val) in h.iter() { + val.next.set(Some(key)); + key.next.set(Some(val)); + } + + let mut c = c_orig.clone(); + c.curr_mark = 30; + for (key, _) in h.iter() { + c.curr_mark += 1; + c.saw_prev_marked = false; + key.for_each_child(&mut c); + assert!(c.saw_prev_marked); + } + + if PRINT { println!(""); } + + // Cycle 4: { h -> (hmk0,hmv0,hmk1,hmv1), {hmk0,hmv0,hmk1,hmv1} -> h } + + let mut h: HashMap = HashMap::new(); + h.insert(Named::new("hmk0"), Named::new("hmv0")); + h.insert(Named::new("hmk0"), Named::new("hmv0")); + for (key, val) in h.iter() { + val.contents.set(Some(&h)); + key.contents.set(Some(&h)); + } + + let mut c = c_orig.clone(); + c.max_depth = 2; + c.curr_mark = 40; + for (key, _) in h.iter() { + c.curr_mark += 1; + c.saw_prev_marked = false; + key.for_each_child(&mut c); + assert!(c.saw_prev_marked); + // break; + } + + if PRINT { println!(""); } + + // Cycle 5: { vd[0] -> vd[1], vd[1] -> vd[0] }; + // does not exercise vd itself + let mut vd: VecDeque = VecDeque::new(); + vd.push_back(Named::new("d0")); + vd.push_back(Named::new("d1")); + vd[0].next.set(Some(&vd[1])); + vd[1].next.set(Some(&vd[0])); + + let mut c = c_orig.clone(); + c.curr_mark = 50; + assert!(!c.saw_prev_marked); + vd[0].for_each_child(&mut c); + assert!(c.saw_prev_marked); + + if PRINT { println!(""); } + + // Cycle 6: { vd -> (vd0, vd1), {vd0, vd1} -> vd } + let mut vd: VecDeque = VecDeque::new(); + vd.push_back(Named::new("vd0")); + vd.push_back(Named::new("vd1")); + vd[0].contents.set(Some(&vd)); + vd[1].contents.set(Some(&vd)); + + let mut c = c_orig.clone(); + c.curr_mark = 60; + assert!(!c.saw_prev_marked); + vd[0].for_each_child(&mut c); + assert!(c.saw_prev_marked); + + if PRINT { println!(""); } + + // Cycle 7: { vm -> (vm0, vm1), {vm0, vm1} -> vm } + let mut vm: VecMap = VecMap::new(); + vm.insert(0, Named::new("vm0")); + vm.insert(1, Named::new("vm1")); + vm[0].contents.set(Some(&vm)); + vm[1].contents.set(Some(&vm)); + + let mut c = c_orig.clone(); + c.curr_mark = 70; + assert!(!c.saw_prev_marked); + vm[0].for_each_child(&mut c); + assert!(c.saw_prev_marked); + + if PRINT { println!(""); } + + // Cycle 8: { ll -> (ll0, ll1), {ll0, ll1} -> ll } + let mut ll: LinkedList = LinkedList::new(); + ll.push_back(Named::new("ll0")); + ll.push_back(Named::new("ll1")); + for e in &ll { + e.contents.set(Some(&ll)); + } + + let mut c = c_orig.clone(); + c.curr_mark = 80; + for e in &ll { + c.curr_mark += 1; + c.saw_prev_marked = false; + e.for_each_child(&mut c); + assert!(c.saw_prev_marked); + // break; + } + + if PRINT { println!(""); } + + // Cycle 9: { bh -> (bh0, bh1), {bh0, bh1} -> bh } + let mut bh: BinaryHeap = BinaryHeap::new(); + bh.push(Named::new("bh0")); + bh.push(Named::new("bh1")); + for b in bh.iter() { + b.contents.set(Some(&bh)); + } + + let mut c = c_orig.clone(); + c.curr_mark = 90; + for b in &bh { + c.curr_mark += 1; + c.saw_prev_marked = false; + b.for_each_child(&mut c); + assert!(c.saw_prev_marked); + // break; + } + + if PRINT { println!(""); } + + // Cycle 10: { btm -> (btk0, btv1), {bt0, bt1} -> btm } + let mut btm: BTreeMap = BTreeMap::new(); + btm.insert(Named::new("btk0"), Named::new("btv0")); + btm.insert(Named::new("btk1"), Named::new("btv1")); + for (k, v) in btm.iter() { + k.contents.set(Some(&btm)); + v.contents.set(Some(&btm)); + } + + let mut c = c_orig.clone(); + c.curr_mark = 100; + for (k, _) in &btm { + c.curr_mark += 1; + c.saw_prev_marked = false; + k.for_each_child(&mut c); + assert!(c.saw_prev_marked); + // break; + } + + if PRINT { println!(""); } + + // Cycle 10: { bts -> (bts0, bts1), {bts0, bts1} -> btm } + let mut bts: BTreeSet = BTreeSet::new(); + bts.insert(Named::new("bts0")); + bts.insert(Named::new("bts1")); + for v in bts.iter() { + v.contents.set(Some(&bts)); + } + + let mut c = c_orig.clone(); + c.curr_mark = 100; + for b in &bts { + c.curr_mark += 1; + c.saw_prev_marked = false; + b.for_each_child(&mut c); + assert!(c.saw_prev_marked); + // break; + } +} + +trait Named { + fn new(&'static str) -> Self; + fn name(&self) -> &str; +} + +trait Marked { + fn mark(&self) -> M; + fn set_mark(&self, mark: M); +} + +struct S<'a> { + name: &'static str, + mark: Cell, + next: Cell>>, +} + +impl<'a> Named for S<'a> { + fn new<'b>(name: &'static str) -> S<'b> { + S { name: name, mark: Cell::new(0), next: Cell::new(None) } + } + fn name(&self) -> &str { self.name } +} + +impl<'a> Marked for S<'a> { + fn mark(&self) -> u32 { self.mark.get() } + fn set_mark(&self, mark: u32) { self.mark.set(mark); } +} + +struct V<'a> { + name: &'static str, + mark: Cell, + contents: Vec>>>, +} + +impl<'a> Named for V<'a> { + fn new<'b>(name: &'static str) -> V<'b> { + V { name: name, + mark: Cell::new(0), + contents: vec![Cell::new(None), Cell::new(None)] + } + } + fn name(&self) -> &str { self.name } +} + +impl<'a> Marked for V<'a> { + fn mark(&self) -> u32 { self.mark.get() } + fn set_mark(&self, mark: u32) { self.mark.set(mark); } +} + +#[derive(Eq)] +struct H<'a> { + name: &'static str, + mark: Cell, + next: Cell>>, +} + +impl<'a> Named for H<'a> { + fn new<'b>(name: &'static str) -> H<'b> { + H { name: name, mark: Cell::new(0), next: Cell::new(None) } + } + fn name(&self) -> &str { self.name } +} + +impl<'a> Marked for H<'a> { + fn mark(&self) -> u32 { self.mark.get() } + fn set_mark(&self, mark: u32) { self.mark.set(mark); } +} + +impl<'a> PartialEq for H<'a> { + fn eq(&self, rhs: &H<'a>) -> bool { + self.name == rhs.name + } +} + +impl<'a> Hash for H<'a> { + fn hash(&self, state: &mut H) { + self.name.hash(state) + } +} + +#[derive(Eq)] +struct HM<'a> { + name: &'static str, + mark: Cell, + contents: Cell, HM<'a>>>>, +} + +impl<'a> Named for HM<'a> { + fn new<'b>(name: &'static str) -> HM<'b> { + HM { name: name, + mark: Cell::new(0), + contents: Cell::new(None) + } + } + fn name(&self) -> &str { self.name } +} + +impl<'a> Marked for HM<'a> { + fn mark(&self) -> u32 { self.mark.get() } + fn set_mark(&self, mark: u32) { self.mark.set(mark); } +} + +impl<'a> PartialEq for HM<'a> { + fn eq(&self, rhs: &HM<'a>) -> bool { + self.name == rhs.name + } +} + +impl<'a> Hash for HM<'a> { + fn hash(&self, state: &mut H) { + self.name.hash(state) + } +} + + +struct VD<'a> { + name: &'static str, + mark: Cell, + contents: Cell>>>, +} + +impl<'a> Named for VD<'a> { + fn new<'b>(name: &'static str) -> VD<'b> { + VD { name: name, + mark: Cell::new(0), + contents: Cell::new(None) + } + } + fn name(&self) -> &str { self.name } +} + +impl<'a> Marked for VD<'a> { + fn mark(&self) -> u32 { self.mark.get() } + fn set_mark(&self, mark: u32) { self.mark.set(mark); } +} + +struct VM<'a> { + name: &'static str, + mark: Cell, + contents: Cell>>>, +} + +impl<'a> Named for VM<'a> { + fn new<'b>(name: &'static str) -> VM<'b> { + VM { name: name, + mark: Cell::new(0), + contents: Cell::new(None) + } + } + fn name(&self) -> &str { self.name } +} + +impl<'a> Marked for VM<'a> { + fn mark(&self) -> u32 { self.mark.get() } + fn set_mark(&self, mark: u32) { self.mark.set(mark); } +} + +struct LL<'a> { + name: &'static str, + mark: Cell, + contents: Cell>>>, +} + +impl<'a> Named for LL<'a> { + fn new<'b>(name: &'static str) -> LL<'b> { + LL { name: name, + mark: Cell::new(0), + contents: Cell::new(None) + } + } + fn name(&self) -> &str { self.name } +} + +impl<'a> Marked for LL<'a> { + fn mark(&self) -> u32 { self.mark.get() } + fn set_mark(&self, mark: u32) { self.mark.set(mark); } +} + +struct BH<'a> { + name: &'static str, + mark: Cell, + contents: Cell>>>, +} + +impl<'a> Named for BH<'a> { + fn new<'b>(name: &'static str) -> BH<'b> { + BH { name: name, + mark: Cell::new(0), + contents: Cell::new(None) + } + } + fn name(&self) -> &str { self.name } +} + +impl<'a> Marked for BH<'a> { + fn mark(&self) -> u32 { self.mark.get() } + fn set_mark(&self, mark: u32) { self.mark.set(mark); } +} + +impl<'a> Eq for BH<'a> { } + +impl<'a> PartialEq for BH<'a> { + fn eq(&self, rhs: &BH<'a>) -> bool { + self.name == rhs.name + } +} + +impl<'a> PartialOrd for BH<'a> { + fn partial_cmp(&self, rhs: &BH<'a>) -> Option { + Some(self.cmp(rhs)) + } +} + +impl<'a> Ord for BH<'a> { + fn cmp(&self, rhs: &BH<'a>) -> Ordering { + self.name.cmp(rhs.name) + } +} + +struct BTM<'a> { + name: &'static str, + mark: Cell, + contents: Cell, BTM<'a>>>>, +} + +impl<'a> Named for BTM<'a> { + fn new<'b>(name: &'static str) -> BTM<'b> { + BTM { name: name, + mark: Cell::new(0), + contents: Cell::new(None) + } + } + fn name(&self) -> &str { self.name } +} + +impl<'a> Marked for BTM<'a> { + fn mark(&self) -> u32 { self.mark.get() } + fn set_mark(&self, mark: u32) { self.mark.set(mark); } +} + +impl<'a> Eq for BTM<'a> { } + +impl<'a> PartialEq for BTM<'a> { + fn eq(&self, rhs: &BTM<'a>) -> bool { + self.name == rhs.name + } +} + +impl<'a> PartialOrd for BTM<'a> { + fn partial_cmp(&self, rhs: &BTM<'a>) -> Option { + Some(self.cmp(rhs)) + } +} + +impl<'a> Ord for BTM<'a> { + fn cmp(&self, rhs: &BTM<'a>) -> Ordering { + self.name.cmp(rhs.name) + } +} + +struct BTS<'a> { + name: &'static str, + mark: Cell, + contents: Cell>>>, +} + +impl<'a> Named for BTS<'a> { + fn new<'b>(name: &'static str) -> BTS<'b> { + BTS { name: name, + mark: Cell::new(0), + contents: Cell::new(None) + } + } + fn name(&self) -> &str { self.name } +} + +impl<'a> Marked for BTS<'a> { + fn mark(&self) -> u32 { self.mark.get() } + fn set_mark(&self, mark: u32) { self.mark.set(mark); } +} + +impl<'a> Eq for BTS<'a> { } + +impl<'a> PartialEq for BTS<'a> { + fn eq(&self, rhs: &BTS<'a>) -> bool { + self.name == rhs.name + } +} + +impl<'a> PartialOrd for BTS<'a> { + fn partial_cmp(&self, rhs: &BTS<'a>) -> Option { + Some(self.cmp(rhs)) + } +} + +impl<'a> Ord for BTS<'a> { + fn cmp(&self, rhs: &BTS<'a>) -> Ordering { + self.name.cmp(rhs.name) + } +} + + +trait Context { + fn should_act(&self) -> bool; + fn increase_visited(&mut self); + fn increase_skipped(&mut self); + fn increase_depth(&mut self); + fn decrease_depth(&mut self); +} + +trait PrePost { + fn pre(&mut self, &T); + fn post(&mut self, &T); + fn hit_limit(&mut self, &T); +} + +trait Children<'a> { + fn for_each_child(&self, context: &mut C) + where C: Context + PrePost, Self: Sized; + + fn descend_into_self(&self, context: &mut C) + where C: Context + PrePost, Self: Sized + { + context.pre(self); + if context.should_act() { + context.increase_visited(); + context.increase_depth(); + self.for_each_child(context); + context.decrease_depth(); + } else { + context.hit_limit(self); + context.increase_skipped(); + } + context.post(self); + } + + fn descend<'b, C>(&self, c: &Cell>, context: &mut C) + where C: Context + PrePost, Self: Sized + { + if let Some(r) = c.get() { + r.descend_into_self(context); + } + } +} + +impl<'a> Children<'a> for S<'a> { + fn for_each_child(&self, context: &mut C) + where C: Context + PrePost> + { + self.descend(&self.next, context); + } +} + +impl<'a> Children<'a> for V<'a> { + fn for_each_child(&self, context: &mut C) + where C: Context + PrePost> + { + for r in &self.contents { + self.descend(r, context); + } + } +} + +impl<'a> Children<'a> for H<'a> { + fn for_each_child(&self, context: &mut C) + where C: Context + PrePost> + { + self.descend(&self.next, context); + } +} + +impl<'a> Children<'a> for HM<'a> { + fn for_each_child(&self, context: &mut C) + where C: Context + PrePost> + { + if let Some(ref hm) = self.contents.get() { + for (k, v) in hm.iter() { + for r in &[k, v] { + r.descend_into_self(context); + } + } + } + } +} + +impl<'a> Children<'a> for VD<'a> { + fn for_each_child(&self, context: &mut C) + where C: Context + PrePost> + { + if let Some(ref vd) = self.contents.get() { + for r in vd.iter() { + r.descend_into_self(context); + } + } + } +} + +impl<'a> Children<'a> for VM<'a> { + fn for_each_child(&self, context: &mut C) + where C: Context + PrePost> + { + if let Some(ref vd) = self.contents.get() { + for (_idx, r) in vd.iter() { + r.descend_into_self(context); + } + } + } +} + +impl<'a> Children<'a> for LL<'a> { + fn for_each_child(&self, context: &mut C) + where C: Context + PrePost> + { + if let Some(ref ll) = self.contents.get() { + for r in ll.iter() { + r.descend_into_self(context); + } + } + } +} + +impl<'a> Children<'a> for BH<'a> { + fn for_each_child(&self, context: &mut C) + where C: Context + PrePost> + { + if let Some(ref bh) = self.contents.get() { + for r in bh.iter() { + r.descend_into_self(context); + } + } + } +} + +impl<'a> Children<'a> for BTM<'a> { + fn for_each_child(&self, context: &mut C) + where C: Context + PrePost> + { + if let Some(ref bh) = self.contents.get() { + for (k, v) in bh.iter() { + for r in &[k, v] { + r.descend_into_self(context); + } + } + } + } +} + +impl<'a> Children<'a> for BTS<'a> { + fn for_each_child(&self, context: &mut C) + where C: Context + PrePost> + { + if let Some(ref bh) = self.contents.get() { + for r in bh.iter() { + r.descend_into_self(context); + } + } + } +} + +#[derive(Copy, Clone)] +struct ContextData { + curr_depth: usize, + max_depth: usize, + visited: usize, + max_visits: usize, + skipped: usize, + curr_mark: u32, + saw_prev_marked: bool, +} + +impl Context for ContextData { + fn should_act(&self) -> bool { + self.curr_depth < self.max_depth && self.visited < self.max_visits + } + fn increase_visited(&mut self) { self.visited += 1; } + fn increase_skipped(&mut self) { self.skipped += 1; } + fn increase_depth(&mut self) { self.curr_depth += 1; } + fn decrease_depth(&mut self) { self.curr_depth -= 1; } +} + +impl> PrePost for ContextData { + fn pre(&mut self, t: &T) { + for _ in 0..self.curr_depth { + if PRINT { print!(" "); } + } + if PRINT { println!("prev {}", t.name()); } + if t.mark() == self.curr_mark { + for _ in 0..self.curr_depth { + if PRINT { print!(" "); } + } + if PRINT { println!("(probably previously marked)"); } + self.saw_prev_marked = true; + } + t.set_mark(self.curr_mark); + } + fn post(&mut self, t: &T) { + for _ in 0..self.curr_depth { + if PRINT { print!(" "); } + } + if PRINT { println!("post {}", t.name()); } + } + fn hit_limit(&mut self, t: &T) { + for _ in 0..self.curr_depth { + if PRINT { print!(" "); } + } + if PRINT { println!("LIMIT {}", t.name()); } + } +}