crashpad/util/stdlib/aligned_allocator_test.cc
Mark Mentovai f55d18ade6 Add AlignedVector and use it for vector<MEMORY_BASIC_INFORMATION64>
MEMORY_BASIC_INFORMATION64 specifies an alignment of 16, but the
standard allocator used by containers doesn't honor this. Although 16
is the default alignment size used on Windows for x86_64, it's not for
32-bit x86. clang assumed that the alignment of the structure was as
declared, and used an SSE load sequence that required this alignment.

AlignedAllocator is a replacement for std::allocator that allows the
alignment to be specified. AlignedVector is an std::vector<> that uses
AlignedAllocator instead of std::allocator.

BUG=chromium:564691
R=scottmg@chromium.org

Review URL: https://codereview.chromium.org/1498133002 .
2015-12-08 15:38:17 -05:00

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// Copyright 2015 The Crashpad Authors. All rights reserved.
//
// 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 "util/stdlib/aligned_allocator.h"
#include <stdint.h>
#include "gtest/gtest.h"
#if defined(OS_WIN)
#include <crtdbg.h>
#endif
namespace crashpad {
namespace test {
namespace {
bool IsAligned(void* pointer, size_t alignment) {
uintptr_t address = reinterpret_cast<uintptr_t>(pointer);
return (address & (alignment - 1)) == 0;
}
TEST(AlignedAllocator, AlignedVector) {
// Test a structure with natural alignment.
struct NaturalAlignedStruct {
int i;
};
AlignedVector<NaturalAlignedStruct> natural_aligned_vector;
natural_aligned_vector.push_back(NaturalAlignedStruct());
EXPECT_TRUE(
IsAligned(&natural_aligned_vector[0], ALIGNOF(NaturalAlignedStruct)));
natural_aligned_vector.resize(3);
EXPECT_TRUE(
IsAligned(&natural_aligned_vector[0], ALIGNOF(NaturalAlignedStruct)));
EXPECT_TRUE(
IsAligned(&natural_aligned_vector[1], ALIGNOF(NaturalAlignedStruct)));
EXPECT_TRUE(
IsAligned(&natural_aligned_vector[2], ALIGNOF(NaturalAlignedStruct)));
// Test a structure that declares its own alignment.
struct ALIGNAS(32) AlignedStruct {
int i;
};
ASSERT_EQ(32u, ALIGNOF(AlignedStruct));
AlignedVector<AlignedStruct> aligned_vector;
aligned_vector.push_back(AlignedStruct());
EXPECT_TRUE(IsAligned(&aligned_vector[0], ALIGNOF(AlignedStruct)));
aligned_vector.resize(3);
EXPECT_TRUE(IsAligned(&aligned_vector[0], ALIGNOF(AlignedStruct)));
EXPECT_TRUE(IsAligned(&aligned_vector[1], ALIGNOF(AlignedStruct)));
EXPECT_TRUE(IsAligned(&aligned_vector[2], ALIGNOF(AlignedStruct)));
// Try a custom alignment. Since the structure itself doesnt specify an
// alignment constraint, only the base address will be aligned to the
// requested boundary.
AlignedVector<NaturalAlignedStruct, 64> custom_aligned_vector;
custom_aligned_vector.push_back(NaturalAlignedStruct());
EXPECT_TRUE(IsAligned(&custom_aligned_vector[0], 64));
// Try a structure with a pretty big alignment request.
struct ALIGNAS(1024) BigAlignedStruct {
int i;
};
ASSERT_EQ(1024u, ALIGNOF(BigAlignedStruct));
AlignedVector<BigAlignedStruct> big_aligned_vector;
big_aligned_vector.push_back(BigAlignedStruct());
EXPECT_TRUE(IsAligned(&big_aligned_vector[0], ALIGNOF(BigAlignedStruct)));
big_aligned_vector.resize(3);
EXPECT_TRUE(IsAligned(&big_aligned_vector[0], ALIGNOF(BigAlignedStruct)));
EXPECT_TRUE(IsAligned(&big_aligned_vector[1], ALIGNOF(BigAlignedStruct)));
EXPECT_TRUE(IsAligned(&big_aligned_vector[2], ALIGNOF(BigAlignedStruct)));
}
void BadAlignmentTest() {
#if defined(OS_WIN)
// Suppress the assertion MessageBox() normally displayed by the CRT in debug
// mode.
int previous = _CrtSetReportMode(_CRT_ASSERT, _CRTDBG_MODE_DEBUG);
// In release mode, _CrtSetReportMode() is #defined to ((int)0), so |previous|
// would appear unused.
ALLOW_UNUSED_LOCAL(previous);
#endif
// Alignment constraints must be powers of 2. 7 is not valid.
AlignedVector<int, 7> bad_aligned_vector;
bad_aligned_vector.push_back(0);
#if defined(OS_WIN)
_CrtSetReportMode(_CRT_ASSERT, previous);
#endif
}
TEST(AlignedAllocatorDeathTest, BadAlignment) {
ASSERT_DEATH(BadAlignmentTest(), "");
}
} // namespace
} // namespace test
} // namespace crashpad