1 files changed, 113 insertions, 0 deletions
diff --git a/test/example/stack-utils.cpp b/test/example/stack-utils.cpp
index 9ed3e1a8a..b5ac496ca 100644
--- a/test/example/stack-utils.cpp
+++ b/test/example/stack-utils.cpp
@@ -354,6 +354,118 @@ void test_signature_subtype() {
   }
 }
 
+void test_signature_lub() {
+  std::cout << ";; Test stack signature lub\n";
+  {
+    StackSignature a{Type::none, Type::none, StackSignature::Fixed};
+    StackSignature b{Type::none, Type::none, StackSignature::Fixed};
+    assert(StackSignature::haveLeastUpperBound(a, b));
+    assert(StackSignature::getLeastUpperBound(a, b) ==
+           (StackSignature{Type::none, Type::none, StackSignature::Fixed}));
+  }
+  {
+    StackSignature a{Type::none, Type::none, StackSignature::Polymorphic};
+    StackSignature b{Type::none, Type::none, StackSignature::Fixed};
+    assert(StackSignature::haveLeastUpperBound(a, b));
+    assert(StackSignature::getLeastUpperBound(a, b) ==
+           (StackSignature{Type::none, Type::none, StackSignature::Fixed}));
+  }
+  {
+    StackSignature a{Type::none, Type::none, StackSignature::Fixed};
+    StackSignature b{Type::none, Type::none, StackSignature::Polymorphic};
+    assert(StackSignature::haveLeastUpperBound(a, b));
+    assert(StackSignature::getLeastUpperBound(a, b) ==
+           (StackSignature{Type::none, Type::none, StackSignature::Fixed}));
+  }
+  {
+    StackSignature a{Type::i32, Type::none, StackSignature::Polymorphic};
+    StackSignature b{Type::none, Type::i32, StackSignature::Polymorphic};
+    assert(StackSignature::haveLeastUpperBound(a, b));
+    assert(StackSignature::getLeastUpperBound(a, b) ==
+           (StackSignature{Type::i32, Type::i32, StackSignature::Polymorphic}));
+  }
+  {
+    StackSignature a{Type::none, Type::i32, StackSignature::Polymorphic};
+    StackSignature b{Type::i32, Type::none, StackSignature::Polymorphic};
+    assert(StackSignature::haveLeastUpperBound(a, b));
+    assert(StackSignature::getLeastUpperBound(a, b) ==
+           (StackSignature{Type::i32, Type::i32, StackSignature::Polymorphic}));
+  }
+  {
+    StackSignature a{Type::none, Type::externref, StackSignature::Polymorphic};
+    StackSignature b{Type::none, Type::funcref, StackSignature::Polymorphic};
+    assert(StackSignature::haveLeastUpperBound(a, b));
+    assert(
+      StackSignature::getLeastUpperBound(a, b) ==
+      (StackSignature{Type::none, Type::anyref, StackSignature::Polymorphic}));
+  }
+  {
+    StackSignature a{Type::anyref, Type::none, StackSignature::Polymorphic};
+    StackSignature b{Type::funcref, Type::none, StackSignature::Polymorphic};
+    // assert(StackSignature::haveLeastUpperBound(a, b));
+    // assert(StackSignature::getLeastUpperBound(a, b) ==
+    //        (StackSignature{Type::funcref, Type::none,
+    //        StackSignature::Polymorphic}));
+  }
+  {
+    StackSignature a{
+      {Type::i32, Type::funcref}, Type::funcref, StackSignature::Polymorphic};
+    StackSignature b{
+      Type::funcref, {Type::f32, Type::externref}, StackSignature::Polymorphic};
+    assert(StackSignature::haveLeastUpperBound(a, b));
+    assert(StackSignature::getLeastUpperBound(a, b) ==
+           (StackSignature{{Type::i32, Type::funcref},
+                           {Type::f32, Type::anyref},
+                           StackSignature::Polymorphic}));
+  }
+  // No LUB
+  {
+    StackSignature a(Type::none, Type::i32, StackSignature::Fixed);
+    StackSignature b(Type::none, Type::f32, StackSignature::Fixed);
+    assert(!StackSignature::haveLeastUpperBound(a, b));
+  }
+  {
+    StackSignature a(Type::none, Type::i32, StackSignature::Polymorphic);
+    StackSignature b(Type::none, Type::f32, StackSignature::Polymorphic);
+    assert(!StackSignature::haveLeastUpperBound(a, b));
+  }
+  {
+    StackSignature a(Type::i32, Type::none, StackSignature::Fixed);
+    StackSignature b(Type::f32, Type::none, StackSignature::Fixed);
+    // assert(!StackSignature::haveLeastUpperBound(a, b));
+  }
+  {
+    StackSignature a(Type::i32, Type::none, StackSignature::Polymorphic);
+    StackSignature b(Type::f32, Type::none, StackSignature::Polymorphic);
+    // assert(!StackSignature::haveLeastUpperBound(a, b));
+  }
+  {
+    StackSignature a(Type::none, Type::none, StackSignature::Fixed);
+    StackSignature b(Type::none, Type::i32, StackSignature::Polymorphic);
+    assert(!StackSignature::haveLeastUpperBound(a, b));
+  }
+  {
+    StackSignature a(Type::none, Type::none, StackSignature::Fixed);
+    StackSignature b(Type::i32, Type::none, StackSignature::Polymorphic);
+    assert(!StackSignature::haveLeastUpperBound(a, b));
+  }
+  {
+    StackSignature a{Type::none, Type::i32, StackSignature::Fixed};
+    StackSignature b{Type::i32, Type::none, StackSignature::Fixed};
+    assert(!StackSignature::haveLeastUpperBound(a, b));
+  }
+  {
+    StackSignature a{Type::none, Type::i32, StackSignature::Polymorphic};
+    StackSignature b{Type::i32, Type::none, StackSignature::Fixed};
+    assert(!StackSignature::haveLeastUpperBound(a, b));
+  }
+  {
+    StackSignature a{Type::none, Type::i32, StackSignature::Fixed};
+    StackSignature b{Type::i32, Type::none, StackSignature::Polymorphic};
+    assert(!StackSignature::haveLeastUpperBound(a, b));
+  }
+}
+
 void test_stack_flow() {
   std::cout << ";; Test stack flow\n";
   {
@@ -493,5 +605,6 @@ int main() {
   test_stack_signatures();
   test_signature_composition();
   test_signature_subtype();
+  test_signature_lub();
   test_stack_flow();
 }