[libc-commits] [libc] [libc][stdlib] Add Block class (PR #94407)

[Michael Jones via libc-commits]

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@@ -0,0 +1,560 @@
+//===-- Unittests for a block of memory -------------------------*- C++ -*-===//
+//
+// 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 <stddef.h>
+
+#include "src/stdlib/block.h"
+
+#include "src/__support/CPP/array.h"
+#include "src/__support/CPP/span.h"
+#include "src/string/memcpy.h"
+#include "test/UnitTest/Test.h"
+
+// Test fixtures.
+using LargeOffsetBlock = LIBC_NAMESPACE::Block<uint64_t>;
+using SmallOffsetBlock = LIBC_NAMESPACE::Block<uint16_t>;
+
+// Macro to provide type-parameterized tests for the various block types above.
+#define TEST_FOR_EACH_BLOCK_TYPE(TestCase)                                     \
+  class LlvmLibcBlockTest##TestCase : public LIBC_NAMESPACE::testing::Test {   \
+  public:                                                                      \
+    template <typename BlockType> void RunTest();                              \
+  };                                                                           \
+  TEST_F(LlvmLibcBlockTest##TestCase, TestCase) {                              \
+    RunTest<LargeOffsetBlock>();                                               \
+    RunTest<SmallOffsetBlock>();                                               \
+  }                                                                            \
+  template <typename BlockType> void LlvmLibcBlockTest##TestCase::RunTest()
+
+using LIBC_NAMESPACE::cpp::array;
+using LIBC_NAMESPACE::cpp::byte;
+using LIBC_NAMESPACE::cpp::span;
+
+TEST_FOR_EACH_BLOCK_TYPE(CanCreateSingleAlignedBlock) {
+  constexpr size_t kN = 1024;
+  alignas(BlockType::kAlignment) array<byte, kN> bytes;
+
+  auto result = BlockType::Init(bytes);
+  ASSERT_TRUE(result.has_value());
+  BlockType *block = *result;
+
+  EXPECT_EQ(block->OuterSize(), kN);
+  EXPECT_EQ(block->InnerSize(), kN - BlockType::kBlockOverhead);
+  EXPECT_EQ(block->Prev(), static_cast<BlockType *>(nullptr));
+  EXPECT_EQ(block->Next(), static_cast<BlockType *>(nullptr));
+  EXPECT_FALSE(block->Used());
+  EXPECT_TRUE(block->Last());
+}
+
+TEST_FOR_EACH_BLOCK_TYPE(CanCreateUnalignedSingleBlock) {
+  constexpr size_t kN = 1024;
+
+  // Force alignment, so we can un-force it below
+  alignas(BlockType::kAlignment) array<byte, kN> bytes;
+  span<byte> aligned(bytes);
+
+  auto result = BlockType::Init(aligned.subspan(1));
+  EXPECT_TRUE(result.has_value());
+}
+
+TEST_FOR_EACH_BLOCK_TYPE(CannotCreateTooSmallBlock) {
+  array<byte, 2> bytes;
+  auto result = BlockType::Init(bytes);
+  EXPECT_FALSE(result.has_value());
+}
+
+TEST(LlvmLibcBlockTest, CannotCreateTooLargeBlock) {
+  using BlockType = LIBC_NAMESPACE::Block<uint8_t>;
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michaelrj-google wrote:

I don't see a comment on this test, did it not get pushed?

https://github.com/llvm/llvm-project/pull/94407