--- /dev/null
+// 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 <LICENSE-APACHE or
+// http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
+// <LICENSE-MIT or http://opensource.org/licenses/MIT>, 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<S> = 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<H,H> = 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<HM,HM> = 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<S> = 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<VD> = 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<VM> = 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<LL> = 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<BH> = 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<BTM, BTM> = 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<BTS> = 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<M> {
+ fn mark(&self) -> M;
+ fn set_mark(&self, mark: M);
+}
+
+struct S<'a> {
+ name: &'static str,
+ mark: Cell<u32>,
+ next: Cell<Option<&'a S<'a>>>,
+}
+
+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<u32> 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<u32>,
+ contents: Vec<Cell<Option<&'a V<'a>>>>,
+}
+
+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<u32> 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<u32>,
+ next: Cell<Option<&'a H<'a>>>,
+}
+
+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<u32> 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<H: Hasher>(&self, state: &mut H) {
+ self.name.hash(state)
+ }
+}
+
+#[derive(Eq)]
+struct HM<'a> {
+ name: &'static str,
+ mark: Cell<u32>,
+ contents: Cell<Option<&'a HashMap<HM<'a>, 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<u32> 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<H: Hasher>(&self, state: &mut H) {
+ self.name.hash(state)
+ }
+}
+
+
+struct VD<'a> {
+ name: &'static str,
+ mark: Cell<u32>,
+ contents: Cell<Option<&'a VecDeque<VD<'a>>>>,
+}
+
+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<u32> 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<u32>,
+ contents: Cell<Option<&'a VecMap<VM<'a>>>>,
+}
+
+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<u32> 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<u32>,
+ contents: Cell<Option<&'a LinkedList<LL<'a>>>>,
+}
+
+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<u32> 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<u32>,
+ contents: Cell<Option<&'a BinaryHeap<BH<'a>>>>,
+}
+
+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<u32> 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<Ordering> {
+ 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<u32>,
+ contents: Cell<Option<&'a BTreeMap<BTM<'a>, 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<u32> 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<Ordering> {
+ 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<u32>,
+ contents: Cell<Option<&'a BTreeSet<BTS<'a>>>>,
+}
+
+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<u32> 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<Ordering> {
+ 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<T> {
+ fn pre(&mut self, &T);
+ fn post(&mut self, &T);
+ fn hit_limit(&mut self, &T);
+}
+
+trait Children<'a> {
+ fn for_each_child<C>(&self, context: &mut C)
+ where C: Context + PrePost<Self>, Self: Sized;
+
+ fn descend_into_self<C>(&self, context: &mut C)
+ where C: Context + PrePost<Self>, 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<Option<&'b Self>>, context: &mut C)
+ where C: Context + PrePost<Self>, Self: Sized
+ {
+ if let Some(r) = c.get() {
+ r.descend_into_self(context);
+ }
+ }
+}
+
+impl<'a> Children<'a> for S<'a> {
+ fn for_each_child<C>(&self, context: &mut C)
+ where C: Context + PrePost<S<'a>>
+ {
+ self.descend(&self.next, context);
+ }
+}
+
+impl<'a> Children<'a> for V<'a> {
+ fn for_each_child<C>(&self, context: &mut C)
+ where C: Context + PrePost<V<'a>>
+ {
+ for r in &self.contents {
+ self.descend(r, context);
+ }
+ }
+}
+
+impl<'a> Children<'a> for H<'a> {
+ fn for_each_child<C>(&self, context: &mut C)
+ where C: Context + PrePost<H<'a>>
+ {
+ self.descend(&self.next, context);
+ }
+}
+
+impl<'a> Children<'a> for HM<'a> {
+ fn for_each_child<C>(&self, context: &mut C)
+ where C: Context + PrePost<HM<'a>>
+ {
+ 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<C>(&self, context: &mut C)
+ where C: Context + PrePost<VD<'a>>
+ {
+ 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<C>(&self, context: &mut C)
+ where C: Context + PrePost<VM<'a>>
+ {
+ 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<C>(&self, context: &mut C)
+ where C: Context + PrePost<LL<'a>>
+ {
+ 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<C>(&self, context: &mut C)
+ where C: Context + PrePost<BH<'a>>
+ {
+ 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<C>(&self, context: &mut C)
+ where C: Context + PrePost<BTM<'a>>
+ {
+ 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<C>(&self, context: &mut C)
+ where C: Context + PrePost<BTS<'a>>
+ {
+ 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<T:Named+Marked<u32>> PrePost<T> 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()); }
+ }
+}
projects / rust.git / commitdiff