Update upstream source from tag 'upstream/1.52.1+dfsg1'

[rustc.git] / vendor / rustc-ap-rustc_data_structures / src / transitive_relation / tests.rs

diff --git a/vendor/rustc-ap-rustc_data_structures/src/transitive_relation/tests.rs b/vendor/rustc-ap-rustc_data_structures/src/transitive_relation/tests.rs
new file mode 100644 (file)
index 0000000..ca90ba1
--- /dev/null
+++ b/vendor/rustc-ap-rustc_data_structures/src/transitive_relation/tests.rs
@@ -0,0 +1,354 @@
+use super::*;
+
+#[test]
+fn test_one_step() {
+    let mut relation = TransitiveRelation::default();
+    relation.add("a", "b");
+    relation.add("a", "c");
+    assert!(relation.contains(&"a", &"c"));
+    assert!(relation.contains(&"a", &"b"));
+    assert!(!relation.contains(&"b", &"a"));
+    assert!(!relation.contains(&"a", &"d"));
+}
+
+#[test]
+fn test_many_steps() {
+    let mut relation = TransitiveRelation::default();
+    relation.add("a", "b");
+    relation.add("a", "c");
+    relation.add("a", "f");
+
+    relation.add("b", "c");
+    relation.add("b", "d");
+    relation.add("b", "e");
+
+    relation.add("e", "g");
+
+    assert!(relation.contains(&"a", &"b"));
+    assert!(relation.contains(&"a", &"c"));
+    assert!(relation.contains(&"a", &"d"));
+    assert!(relation.contains(&"a", &"e"));
+    assert!(relation.contains(&"a", &"f"));
+    assert!(relation.contains(&"a", &"g"));
+
+    assert!(relation.contains(&"b", &"g"));
+
+    assert!(!relation.contains(&"a", &"x"));
+    assert!(!relation.contains(&"b", &"f"));
+}
+
+#[test]
+fn mubs_triangle() {
+    // a -> tcx
+    //      ^
+    //      |
+    //      b
+    let mut relation = TransitiveRelation::default();
+    relation.add("a", "tcx");
+    relation.add("b", "tcx");
+    assert_eq!(relation.minimal_upper_bounds(&"a", &"b"), vec![&"tcx"]);
+    assert_eq!(relation.parents(&"a"), vec![&"tcx"]);
+    assert_eq!(relation.parents(&"b"), vec![&"tcx"]);
+}
+
+#[test]
+fn mubs_best_choice1() {
+    // 0 -> 1 <- 3
+    // |    ^    |
+    // |    |    |
+    // +--> 2 <--+
+    //
+    // mubs(0,3) = [1]
+
+    // This tests a particular state in the algorithm, in which we
+    // need the second pare down call to get the right result (after
+    // intersection, we have [1, 2], but 2 -> 1).
+
+    let mut relation = TransitiveRelation::default();
+    relation.add("0", "1");
+    relation.add("0", "2");
+
+    relation.add("2", "1");
+
+    relation.add("3", "1");
+    relation.add("3", "2");
+
+    assert_eq!(relation.minimal_upper_bounds(&"0", &"3"), vec![&"2"]);
+    assert_eq!(relation.parents(&"0"), vec![&"2"]);
+    assert_eq!(relation.parents(&"2"), vec![&"1"]);
+    assert!(relation.parents(&"1").is_empty());
+}
+
+#[test]
+fn mubs_best_choice2() {
+    // 0 -> 1 <- 3
+    // |    |    |
+    // |    v    |
+    // +--> 2 <--+
+    //
+    // mubs(0,3) = [2]
+
+    // Like the precedecing test, but in this case intersection is [2,
+    // 1], and hence we rely on the first pare down call.
+
+    let mut relation = TransitiveRelation::default();
+    relation.add("0", "1");
+    relation.add("0", "2");
+
+    relation.add("1", "2");
+
+    relation.add("3", "1");
+    relation.add("3", "2");
+
+    assert_eq!(relation.minimal_upper_bounds(&"0", &"3"), vec![&"1"]);
+    assert_eq!(relation.parents(&"0"), vec![&"1"]);
+    assert_eq!(relation.parents(&"1"), vec![&"2"]);
+    assert!(relation.parents(&"2").is_empty());
+}
+
+#[test]
+fn mubs_no_best_choice() {
+    // in this case, the intersection yields [1, 2], and the "pare
+    // down" calls find nothing to remove.
+    let mut relation = TransitiveRelation::default();
+    relation.add("0", "1");
+    relation.add("0", "2");
+
+    relation.add("3", "1");
+    relation.add("3", "2");
+
+    assert_eq!(relation.minimal_upper_bounds(&"0", &"3"), vec![&"1", &"2"]);
+    assert_eq!(relation.parents(&"0"), vec![&"1", &"2"]);
+    assert_eq!(relation.parents(&"3"), vec![&"1", &"2"]);
+}
+
+#[test]
+fn mubs_best_choice_scc() {
+    // in this case, 1 and 2 form a cycle; we pick arbitrarily (but
+    // consistently).
+
+    let mut relation = TransitiveRelation::default();
+    relation.add("0", "1");
+    relation.add("0", "2");
+
+    relation.add("1", "2");
+    relation.add("2", "1");
+
+    relation.add("3", "1");
+    relation.add("3", "2");
+
+    assert_eq!(relation.minimal_upper_bounds(&"0", &"3"), vec![&"1"]);
+    assert_eq!(relation.parents(&"0"), vec![&"1"]);
+}
+
+#[test]
+fn pdub_crisscross() {
+    // diagonal edges run left-to-right
+    // a -> a1 -> x
+    //   \/       ^
+    //   /\       |
+    // b -> b1 ---+
+
+    let mut relation = TransitiveRelation::default();
+    relation.add("a", "a1");
+    relation.add("a", "b1");
+    relation.add("b", "a1");
+    relation.add("b", "b1");
+    relation.add("a1", "x");
+    relation.add("b1", "x");
+
+    assert_eq!(relation.minimal_upper_bounds(&"a", &"b"), vec![&"a1", &"b1"]);
+    assert_eq!(relation.postdom_upper_bound(&"a", &"b"), Some(&"x"));
+    assert_eq!(relation.postdom_parent(&"a"), Some(&"x"));
+    assert_eq!(relation.postdom_parent(&"b"), Some(&"x"));
+}
+
+#[test]
+fn pdub_crisscross_more() {
+    // diagonal edges run left-to-right
+    // a -> a1 -> a2 -> a3 -> x
+    //   \/    \/             ^
+    //   /\    /\             |
+    // b -> b1 -> b2 ---------+
+
+    let mut relation = TransitiveRelation::default();
+    relation.add("a", "a1");
+    relation.add("a", "b1");
+    relation.add("b", "a1");
+    relation.add("b", "b1");
+
+    relation.add("a1", "a2");
+    relation.add("a1", "b2");
+    relation.add("b1", "a2");
+    relation.add("b1", "b2");
+
+    relation.add("a2", "a3");
+
+    relation.add("a3", "x");
+    relation.add("b2", "x");
+
+    assert_eq!(relation.minimal_upper_bounds(&"a", &"b"), vec![&"a1", &"b1"]);
+    assert_eq!(relation.minimal_upper_bounds(&"a1", &"b1"), vec![&"a2", &"b2"]);
+    assert_eq!(relation.postdom_upper_bound(&"a", &"b"), Some(&"x"));
+
+    assert_eq!(relation.postdom_parent(&"a"), Some(&"x"));
+    assert_eq!(relation.postdom_parent(&"b"), Some(&"x"));
+}
+
+#[test]
+fn pdub_lub() {
+    // a -> a1 -> x
+    //            ^
+    //            |
+    // b -> b1 ---+
+
+    let mut relation = TransitiveRelation::default();
+    relation.add("a", "a1");
+    relation.add("b", "b1");
+    relation.add("a1", "x");
+    relation.add("b1", "x");
+
+    assert_eq!(relation.minimal_upper_bounds(&"a", &"b"), vec![&"x"]);
+    assert_eq!(relation.postdom_upper_bound(&"a", &"b"), Some(&"x"));
+
+    assert_eq!(relation.postdom_parent(&"a"), Some(&"a1"));
+    assert_eq!(relation.postdom_parent(&"b"), Some(&"b1"));
+    assert_eq!(relation.postdom_parent(&"a1"), Some(&"x"));
+    assert_eq!(relation.postdom_parent(&"b1"), Some(&"x"));
+}
+
+#[test]
+fn mubs_intermediate_node_on_one_side_only() {
+    // a -> c -> d
+    //           ^
+    //           |
+    //           b
+
+    // "digraph { a -> c -> d; b -> d; }",
+    let mut relation = TransitiveRelation::default();
+    relation.add("a", "c");
+    relation.add("c", "d");
+    relation.add("b", "d");
+
+    assert_eq!(relation.minimal_upper_bounds(&"a", &"b"), vec![&"d"]);
+}
+
+#[test]
+fn mubs_scc_1() {
+    // +-------------+
+    // |    +----+   |
+    // |    v    |   |
+    // a -> c -> d <-+
+    //           ^
+    //           |
+    //           b
+
+    // "digraph { a -> c -> d; d -> c; a -> d; b -> d; }",
+    let mut relation = TransitiveRelation::default();
+    relation.add("a", "c");
+    relation.add("c", "d");
+    relation.add("d", "c");
+    relation.add("a", "d");
+    relation.add("b", "d");
+
+    assert_eq!(relation.minimal_upper_bounds(&"a", &"b"), vec![&"c"]);
+}
+
+#[test]
+fn mubs_scc_2() {
+    //      +----+
+    //      v    |
+    // a -> c -> d
+    //      ^    ^
+    //      |    |
+    //      +--- b
+
+    // "digraph { a -> c -> d; d -> c; b -> d; b -> c; }",
+    let mut relation = TransitiveRelation::default();
+    relation.add("a", "c");
+    relation.add("c", "d");
+    relation.add("d", "c");
+    relation.add("b", "d");
+    relation.add("b", "c");
+
+    assert_eq!(relation.minimal_upper_bounds(&"a", &"b"), vec![&"c"]);
+}
+
+#[test]
+fn mubs_scc_3() {
+    //      +---------+
+    //      v         |
+    // a -> c -> d -> e
+    //           ^    ^
+    //           |    |
+    //           b ---+
+
+    // "digraph { a -> c -> d -> e -> c; b -> d; b -> e; }",
+    let mut relation = TransitiveRelation::default();
+    relation.add("a", "c");
+    relation.add("c", "d");
+    relation.add("d", "e");
+    relation.add("e", "c");
+    relation.add("b", "d");
+    relation.add("b", "e");
+
+    assert_eq!(relation.minimal_upper_bounds(&"a", &"b"), vec![&"c"]);
+}
+
+#[test]
+fn mubs_scc_4() {
+    //      +---------+
+    //      v         |
+    // a -> c -> d -> e
+    // |         ^    ^
+    // +---------+    |
+    //                |
+    //           b ---+
+
+    // "digraph { a -> c -> d -> e -> c; a -> d; b -> e; }"
+    let mut relation = TransitiveRelation::default();
+    relation.add("a", "c");
+    relation.add("c", "d");
+    relation.add("d", "e");
+    relation.add("e", "c");
+    relation.add("a", "d");
+    relation.add("b", "e");
+
+    assert_eq!(relation.minimal_upper_bounds(&"a", &"b"), vec![&"c"]);
+}
+
+#[test]
+fn parent() {
+    // An example that was misbehaving in the compiler.
+    //
+    // 4 -> 1 -> 3
+    //   \  |   /
+    //    \ v  /
+    // 2 -> 0
+    //
+    // plus a bunch of self-loops
+    //
+    // Here `->` represents `<=` and `0` is `'static`.
+
+    let pairs = vec![
+        (2, /*->*/ 0),
+        (2, /*->*/ 2),
+        (0, /*->*/ 0),
+        (0, /*->*/ 0),
+        (1, /*->*/ 0),
+        (1, /*->*/ 1),
+        (3, /*->*/ 0),
+        (3, /*->*/ 3),
+        (4, /*->*/ 0),
+        (4, /*->*/ 1),
+        (1, /*->*/ 3),
+    ];
+
+    let mut relation = TransitiveRelation::default();
+    for (a, b) in pairs {
+        relation.add(a, b);
+    }
+
+    let p = relation.postdom_parent(&3);
+    assert_eq!(p, Some(&0));
+}