[llvm] [ADT] Add a unittest for the ScopedHashTable class (PR #120183)

[via llvm-commits]

llvmbot wrote:


<!--LLVM PR SUMMARY COMMENT-->

@llvm/pr-subscribers-llvm-adt

Author: Pavel Samolysov (samolisov)

<details>
<summary>Changes</summary>

The ScopedHashTable class is particularly used to develop string tables for parsers and code convertors. For example, the MLIRGen class from the toy example for MLIR actively uses this class to define scopes for declared variables. To demonstrate common use cases for the ScopedHashTable class as well as to check its behavior in different situations, the unittest has been added.

---
Full diff: https://github.com/llvm/llvm-project/pull/120183.diff


2 Files Affected:

- (modified) llvm/unittests/ADT/CMakeLists.txt (+1) 
- (added) llvm/unittests/ADT/ScopedHashTableTest.cpp (+144) 


``````````diff
diff --git a/llvm/unittests/ADT/CMakeLists.txt b/llvm/unittests/ADT/CMakeLists.txt
index 07568ad0c64e33..dafd73518aedb9 100644
--- a/llvm/unittests/ADT/CMakeLists.txt
+++ b/llvm/unittests/ADT/CMakeLists.txt
@@ -67,6 +67,7 @@ add_llvm_unittest(ADTTests
   SCCIteratorTest.cpp
   STLExtrasTest.cpp
   STLForwardCompatTest.cpp
+  ScopedHashTableTest.cpp
   ScopeExitTest.cpp
   SequenceTest.cpp
   SetOperationsTest.cpp
diff --git a/llvm/unittests/ADT/ScopedHashTableTest.cpp b/llvm/unittests/ADT/ScopedHashTableTest.cpp
new file mode 100644
index 00000000000000..e0dc1f453b3716
--- /dev/null
+++ b/llvm/unittests/ADT/ScopedHashTableTest.cpp
@@ -0,0 +1,144 @@
+//===- ScopedHashTableTest.cpp - ScopedHashTable unit tests ---------------===//
+//
+// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
+// See https://llvm.org/LICENSE.txt for license information.
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
+//
+//===----------------------------------------------------------------------===//
+
+#include "llvm/ADT/ScopedHashTable.h"
+#include "llvm/ADT/StringRef.h"
+#include "gtest/gtest.h"
+#include <memory>
+#include <stack>
+
+using ::llvm::ScopedHashTable;
+using ::llvm::ScopedHashTableScope;
+using ::llvm::StringRef;
+
+using ::testing::Test;
+
+class ScopedHashTableTest : public Test {
+protected:
+  ScopedHashTableTest() { symbolTable.insert(kGlobalName, kGlobalValue); }
+
+  ScopedHashTable<StringRef, StringRef> symbolTable{};
+  ScopedHashTableScope<StringRef, StringRef> globalScope{symbolTable};
+
+  static constexpr StringRef kGlobalName = "global";
+  static constexpr StringRef kGlobalValue = "gvalue";
+  static constexpr StringRef kLocalName = "local";
+  static constexpr StringRef kLocalValue = "lvalue";
+  static constexpr StringRef kLocalValue2 = "lvalue2";
+};
+
+TEST_F(ScopedHashTableTest, AccessWithNoActiveScope) {
+  EXPECT_EQ(symbolTable.count(kGlobalName), 1U);
+}
+
+TEST_F(ScopedHashTableTest, AccessWithAScope) {
+  [[maybe_unused]] ScopedHashTableScope varScope(symbolTable);
+  EXPECT_EQ(symbolTable.count(kGlobalName), 1U);
+}
+
+TEST_F(ScopedHashTableTest, InsertInScope) {
+  [[maybe_unused]] ScopedHashTableScope varScope(symbolTable);
+  symbolTable.insert(kLocalName, kLocalValue);
+  EXPECT_EQ(symbolTable.count(kLocalName), 1U);
+}
+
+TEST_F(ScopedHashTableTest, InsertInLinearSortedScope) {
+  [[maybe_unused]] ScopedHashTableScope varScope(symbolTable);
+  [[maybe_unused]] ScopedHashTableScope varScope2(symbolTable);
+  [[maybe_unused]] ScopedHashTableScope varScope3(symbolTable);
+  symbolTable.insert(kLocalName, kLocalValue);
+  EXPECT_EQ(symbolTable.count(kLocalName), 1U);
+}
+
+TEST_F(ScopedHashTableTest, InsertInOutedScope) {
+  {
+    [[maybe_unused]] ScopedHashTableScope varScope(symbolTable);
+    symbolTable.insert(kLocalName, kLocalValue);
+  }
+  EXPECT_EQ(symbolTable.count(kLocalName), 0U);
+}
+
+TEST_F(ScopedHashTableTest, OverrideInScope) {
+  [[maybe_unused]] ScopedHashTableScope funScope(symbolTable);
+  symbolTable.insert(kLocalName, kLocalValue);
+  {
+    [[maybe_unused]] ScopedHashTableScope varScope(symbolTable);
+    symbolTable.insert(kLocalName, kLocalValue2);
+    EXPECT_EQ(symbolTable.lookup(kLocalName), kLocalValue2);
+  }
+  EXPECT_EQ(symbolTable.lookup(kLocalName), kLocalValue);
+}
+
+TEST_F(ScopedHashTableTest, GetCurScope) {
+  EXPECT_EQ(symbolTable.getCurScope(), &globalScope);
+  {
+    ScopedHashTableScope funScope(symbolTable);
+    ScopedHashTableScope funScope2(symbolTable);
+    EXPECT_EQ(symbolTable.getCurScope(), &funScope2);
+    {
+      ScopedHashTableScope blockScope(symbolTable);
+      EXPECT_EQ(symbolTable.getCurScope(), &blockScope);
+    }
+    EXPECT_EQ(symbolTable.getCurScope(), &funScope2);
+  }
+  EXPECT_EQ(symbolTable.getCurScope(), &globalScope);
+}
+
+TEST_F(ScopedHashTableTest, PopScope) {
+  using SymbolTableScopeTy = ScopedHashTable<StringRef, StringRef>::ScopeTy;
+
+  std::stack<StringRef> ExpectedValues;
+  std::stack<std::unique_ptr<SymbolTableScopeTy>> Scopes;
+
+  Scopes.emplace(std::make_unique<SymbolTableScopeTy>(symbolTable));
+  ExpectedValues.emplace(kLocalValue);
+  symbolTable.insert(kGlobalName, kLocalValue);
+
+  Scopes.emplace(std::make_unique<SymbolTableScopeTy>(symbolTable));
+  ExpectedValues.emplace(kLocalValue2);
+  symbolTable.insert(kGlobalName, kLocalValue2);
+
+  while (symbolTable.getCurScope() != &globalScope) {
+    EXPECT_EQ(symbolTable.getCurScope(), Scopes.top().get());
+    EXPECT_EQ(symbolTable.lookup(kGlobalName), ExpectedValues.top());
+    ExpectedValues.pop();
+    Scopes.pop(); // destructs the SymbolTableScopeTy instance implicitly
+                  // calling Scopes.top()->~SymbolTableScopeTy();
+    EXPECT_NE(symbolTable.getCurScope(), nullptr);
+  }
+  ASSERT_TRUE(ExpectedValues.empty());
+  ASSERT_TRUE(Scopes.empty());
+  EXPECT_EQ(symbolTable.lookup(kGlobalName), kGlobalValue);
+}
+
+TEST_F(ScopedHashTableTest, DISABLED_PopScopeOnStack) {
+  using SymbolTableScopeTy = ScopedHashTable<StringRef, StringRef>::ScopeTy;
+  SymbolTableScopeTy funScope(symbolTable);
+  symbolTable.insert(kGlobalName, kLocalValue);
+  SymbolTableScopeTy funScope2(symbolTable);
+  symbolTable.insert(kGlobalName, kLocalValue2);
+
+  std::stack<StringRef> expectedValues{{kLocalValue, kLocalValue2}};
+  std::stack<SymbolTableScopeTy *> expectedScopes{{&funScope, &funScope2}};
+
+  while (symbolTable.getCurScope() != &globalScope) {
+    EXPECT_EQ(symbolTable.getCurScope(), expectedScopes.top());
+    expectedScopes.pop();
+    EXPECT_EQ(symbolTable.lookup(kGlobalName), expectedValues.top());
+    expectedValues.pop();
+    symbolTable.getCurScope()->~SymbolTableScopeTy();
+    EXPECT_NE(symbolTable.getCurScope(), nullptr);
+  }
+
+  // We have imbalanced scopes here:
+  // Assertion `HT.CurScope == this && "Scope imbalance!"' failed
+  // HT.CurScope is a pointer to the `globalScope` while
+  // `SymbolTableScopeTy.this` is still a pointer to `funScope2`.
+  // There is no way to write an assert on an assert in googletest so that we
+  // mark the test case as DISABLED.
+}

``````````

</details>


https://github.com/llvm/llvm-project/pull/120183