[analysis] Implement a Bool lattice (#6036)

This is a lattice with two elements: `false` is bottom and `true` is top.

Add a new gtest file for testing lattices.

2 files changed, 51 insertions, 0 deletions

diff --git a/test/gtest/CMakeLists.txt b/test/gtest/CMakeLists.txt
index d50d33ac1..b40130760 100644
--- a/test/gtest/CMakeLists.txt
+++ b/test/gtest/CMakeLists.txt
@@ -4,6 +4,7 @@ include_directories(../../src/wasm)
 set(unittest_SOURCES
   cfg.cpp
   dfa_minimization.cpp
+  lattices.cpp
   possible-contents.cpp
   printing.cpp
   stringify.cpp
diff --git a/test/gtest/lattices.cpp b/test/gtest/lattices.cpp
new file mode 100644
index 000000000..f06ba612b
--- /dev/null
+++ b/test/gtest/lattices.cpp
@@ -0,0 +1,50 @@
+/*
+ * Copyright 2023 WebAssembly Community Group participants
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#include "analysis/lattices/bool.h"
+#include "gtest/gtest.h"
+
+using namespace wasm;
+
+TEST(BoolLattice, GetBottom) {
+  analysis::Bool lattice;
+  EXPECT_FALSE(lattice.getBottom());
+}
+
+TEST(BoolLattice, Compare) {
+  analysis::Bool lattice;
+  EXPECT_EQ(lattice.compare(false, false), analysis::EQUAL);
+  EXPECT_EQ(lattice.compare(false, true), analysis::LESS);
+  EXPECT_EQ(lattice.compare(true, false), analysis::GREATER);
+  EXPECT_EQ(lattice.compare(true, true), analysis::EQUAL);
+}
+
+TEST(BoolLattice, Join) {
+  analysis::Bool lattice;
+  bool elem = false;
+
+  EXPECT_FALSE(lattice.join(elem, false));
+  ASSERT_FALSE(elem);
+
+  EXPECT_TRUE(lattice.join(elem, true));
+  ASSERT_TRUE(elem);
+
+  EXPECT_FALSE(lattice.join(elem, false));
+  ASSERT_TRUE(elem);
+
+  EXPECT_FALSE(lattice.join(elem, true));
+  ASSERT_TRUE(elem);
+}