Mojo: Specify/check alignment of pointers more carefully.

mojo/system/memory_unittest.cc

Index: mojo/system/memory_unittest.cc
diff --git a/mojo/system/memory_unittest.cc b/mojo/system/memory_unittest.cc
new file mode 100644
index 0000000000000000000000000000000000000000..b23d50ae7be5ceeed08b3a8ac3cdbfa373bd4c34
--- /dev/null
+++ b/mojo/system/memory_unittest.cc
@@ -0,0 +1,136 @@
+// Copyright 2014 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#include "mojo/system/memory.h"
+
+#include <stddef.h>
+#include <stdint.h>
+
+#include <limits>
+
+#include "mojo/public/c/system/macros.h"
+#include "testing/gtest/include/gtest/gtest.h"
+
+namespace mojo {
+namespace system {
+namespace {
+
+TEST(MemoryTest, Valid) {
+  char my_char;
+  int32_t my_int32;
+  int64_t my_int64;
+  char my_char_array[5];
+  int32_t my_int32_array[5];
+  int64_t my_int64_array[5];
+
+  // |VerifyUserPointer|:
+
+  EXPECT_TRUE(VerifyUserPointer<char>(&my_char));
+  EXPECT_TRUE(VerifyUserPointer<int32_t>(&my_int32));
+  EXPECT_TRUE(VerifyUserPointer<int64_t>(&my_int64));
+
+  // |VerifyUserPointerWithCount|:
+
+  EXPECT_TRUE(VerifyUserPointerWithCount<char>(my_char_array, 5));
+  EXPECT_TRUE(VerifyUserPointerWithCount<int32_t>(my_int32_array, 5));
+  EXPECT_TRUE(VerifyUserPointerWithCount<int64_t>(my_int64_array, 5));
+
+  // It shouldn't care what the pointer is if the count is zero.
+  EXPECT_TRUE(VerifyUserPointerWithCount<char>(NULL, 0));
+  EXPECT_TRUE(VerifyUserPointerWithCount<int32_t>(NULL, 0));
+  EXPECT_TRUE(VerifyUserPointerWithCount<int32_t>(
+                  reinterpret_cast<const int32_t*>(1), 0));
+  EXPECT_TRUE(VerifyUserPointerWithCount<int64_t>(NULL, 0));
+  EXPECT_TRUE(VerifyUserPointerWithCount<int64_t>(
+                  reinterpret_cast<const int64_t*>(1), 0));
+
+  // |VerifyUserPointerWithSize|:
+
+  EXPECT_TRUE(VerifyUserPointerWithSize<1>(&my_char, sizeof(my_char)));
+  EXPECT_TRUE(VerifyUserPointerWithSize<1>(&my_int32, sizeof(my_int32)));
+  EXPECT_TRUE(VerifyUserPointerWithSize<MOJO_ALIGNOF(int32_t)>(
+                  &my_int32, sizeof(my_int32)));
+  EXPECT_TRUE(VerifyUserPointerWithSize<1>(&my_int64, sizeof(my_int64)));
+  EXPECT_TRUE(VerifyUserPointerWithSize<MOJO_ALIGNOF(int64_t)>(
+                  &my_int64, sizeof(my_int64)));
+
+  EXPECT_TRUE(VerifyUserPointerWithSize<1>(my_char_array,
+                                           sizeof(my_char_array)));
+  EXPECT_TRUE(VerifyUserPointerWithSize<1>(my_int32_array,
+                                           sizeof(my_int32_array)));
+  EXPECT_TRUE(VerifyUserPointerWithSize<MOJO_ALIGNOF(int32_t)>(
+                  my_int32_array, sizeof(my_int32_array)));
+  EXPECT_TRUE(VerifyUserPointerWithSize<1>(my_int64_array,
+                                           sizeof(my_int64_array)));
+  EXPECT_TRUE(VerifyUserPointerWithSize<MOJO_ALIGNOF(int64_t)>(
+                  my_int64_array, sizeof(my_int64_array)));
+}
+
+TEST(MemoryTest, Invalid) {
+  // Note: |VerifyUserPointer...()| are defined to be "best effort" checks (and
+  // may always return true). Thus these tests of invalid cases only reflect the
+  // current implementation.
+
+  // These tests depend on |int32_t| and |int64_t| having nontrivial alignment.
+  MOJO_COMPILE_ASSERT(MOJO_ALIGNOF(int32_t) != 1,
+                      int32_t_does_not_have_to_be_aligned);
+  MOJO_COMPILE_ASSERT(MOJO_ALIGNOF(int64_t) != 1,
+                      int64_t_does_not_have_to_be_aligned);
+
+  int32_t my_int32;
+  int64_t my_int64;
+
+  // |VerifyUserPointer|:
+
+  EXPECT_FALSE(VerifyUserPointer<char>(NULL));
+  EXPECT_FALSE(VerifyUserPointer<int32_t>(NULL));
+  EXPECT_FALSE(VerifyUserPointer<int64_t>(NULL));
+
+  // Unaligned:
+  EXPECT_FALSE(VerifyUserPointer<int32_t>(reinterpret_cast<const int32_t*>(1)));
+  EXPECT_FALSE(VerifyUserPointer<int64_t>(reinterpret_cast<const int64_t*>(1)));
+
+  // |VerifyUserPointerWithCount|:
+
+  EXPECT_FALSE(VerifyUserPointerWithCount<char>(NULL, 1));
+  EXPECT_FALSE(VerifyUserPointerWithCount<int32_t>(NULL, 1));
+  EXPECT_FALSE(VerifyUserPointerWithCount<int64_t>(NULL, 1));
+
+  // Unaligned:
+  EXPECT_FALSE(VerifyUserPointerWithCount<int32_t>(
+                   reinterpret_cast<const int32_t*>(1), 1));
+  EXPECT_FALSE(VerifyUserPointerWithCount<int64_t>(
+                   reinterpret_cast<const int64_t*>(1), 1));
+
+  // Count too big:
+  EXPECT_FALSE(VerifyUserPointerWithCount<int32_t>(
+                   &my_int32, std::numeric_limits<size_t>::max()));
+  EXPECT_FALSE(VerifyUserPointerWithCount<int64_t>(
+                   &my_int64, std::numeric_limits<size_t>::max()));
+
+  // |VerifyUserPointerWithSize|:
+
+  EXPECT_FALSE(VerifyUserPointerWithSize<1>(NULL, 1));
+  EXPECT_FALSE(VerifyUserPointerWithSize<4>(NULL, 1));
+  EXPECT_FALSE(VerifyUserPointerWithSize<4>(NULL, 4));
+  EXPECT_FALSE(VerifyUserPointerWithSize<8>(NULL, 1));
+  EXPECT_FALSE(VerifyUserPointerWithSize<8>(NULL, 4));
+  EXPECT_FALSE(VerifyUserPointerWithSize<8>(NULL, 8));
+
+  // Unaligned:
+  EXPECT_FALSE(VerifyUserPointerWithSize<4>(reinterpret_cast<const int32_t*>(1),
+                                            1));
+  EXPECT_FALSE(VerifyUserPointerWithSize<4>(reinterpret_cast<const int32_t*>(1),
+                                            4));
+  EXPECT_FALSE(VerifyUserPointerWithSize<8>(reinterpret_cast<const int32_t*>(1),
+                                            1));
+  EXPECT_FALSE(VerifyUserPointerWithSize<8>(reinterpret_cast<const int32_t*>(1),
+                                            4));
+  EXPECT_FALSE(VerifyUserPointerWithSize<8>(reinterpret_cast<const int32_t*>(1),
+                                            8));
+}
+
+}  // namespace
+}  // namespace system
+}  // namespace mojo