Refactor base/safe_numerics.h

base/safe_numerics_unittest.cc

Index: base/safe_numerics_unittest.cc
===================================================================
--- base/safe_numerics_unittest.cc	(revision 245415)
+++ base/safe_numerics_unittest.cc	(working copy)
@@ -1,279 +0,0 @@
-// Copyright 2013 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 "base/safe_numerics.h"
-
-#include <stdint.h>
-
-#include <limits>
-
-#include "base/compiler_specific.h"
-#include "testing/gtest/include/gtest/gtest.h"
-
-namespace base {
-namespace internal {
-
-// Enumerates the five different conversions types we need to test.
-enum NumericConversionType {
-  SIGN_PRESERVING_VALUE_PRESERVING,
-  SIGN_PRESERVING_NARROW,
-  SIGN_TO_UNSIGN_WIDEN_OR_EQUAL,
-  SIGN_TO_UNSIGN_NARROW,
-  UNSIGN_TO_SIGN_NARROW_OR_EQUAL,
-};
-
-// Template covering the different conversion tests.
-template <typename Dst, typename Src, NumericConversionType conversion>
-struct TestNumericConversion {};
-
-// EXPECT_EQ wrapper providing specific detail on test failures.
-#define TEST_EXPECTED_RANGE(expected, actual) \
-  EXPECT_EQ(expected, RangeCheck<Dst>(actual)) << \
-  "Conversion test: " << src << " value " << actual << \
-  " to " << dst << " on line " << line;
-
-template <typename Dst, typename Src>
-struct TestNumericConversion<Dst, Src, SIGN_PRESERVING_VALUE_PRESERVING> {
-  static void Test(const char *dst, const char *src, int line) {
-    typedef std::numeric_limits<Src> SrcLimits;
-    typedef std::numeric_limits<Dst> DstLimits;
-                   // Integral to floating.
-    COMPILE_ASSERT((DstLimits::is_iec559 && SrcLimits::is_integer) ||
-                   // Not floating to integral and...
-                   (!(DstLimits::is_integer && SrcLimits::is_iec559) &&
-                    // Same sign, same numeric, source is narrower or same.
-                    ((SrcLimits::is_signed == DstLimits::is_signed &&
-                     sizeof(Dst) >= sizeof(Src)) ||
-                    // Or signed destination and source is smaller
-                     (DstLimits::is_signed && sizeof(Dst) > sizeof(Src)))),
-                   comparison_must_be_sign_preserving_and_value_preserving);
-
-    TEST_EXPECTED_RANGE(TYPE_VALID, SrcLimits::max());
-    TEST_EXPECTED_RANGE(TYPE_VALID, static_cast<Src>(1));
-    if (SrcLimits::is_iec559) {
-      TEST_EXPECTED_RANGE(TYPE_VALID, SrcLimits::max() * static_cast<Src>(-1));
-      TEST_EXPECTED_RANGE(TYPE_OVERFLOW, SrcLimits::infinity());
-      TEST_EXPECTED_RANGE(TYPE_UNDERFLOW, SrcLimits::infinity() * -1);
-      TEST_EXPECTED_RANGE(TYPE_INVALID, SrcLimits::quiet_NaN());
-    } else if (std::numeric_limits<Src>::is_signed) {
-      TEST_EXPECTED_RANGE(TYPE_VALID, static_cast<Src>(-1));
-      TEST_EXPECTED_RANGE(TYPE_VALID, SrcLimits::min());
-    }
-  }
-};
-
-template <typename Dst, typename Src>
-struct TestNumericConversion<Dst, Src, SIGN_PRESERVING_NARROW> {
-  static void Test(const char *dst, const char *src, int line) {
-    typedef std::numeric_limits<Src> SrcLimits;
-    typedef std::numeric_limits<Dst> DstLimits;
-    COMPILE_ASSERT(SrcLimits::is_signed == DstLimits::is_signed,
-                   destination_and_source_sign_must_be_the_same);
-    COMPILE_ASSERT(sizeof(Dst) < sizeof(Src) ||
-                   (DstLimits::is_integer && SrcLimits::is_iec559),
-                   destination_must_be_narrower_than_source);
-
-    TEST_EXPECTED_RANGE(TYPE_OVERFLOW, SrcLimits::max());
-    TEST_EXPECTED_RANGE(TYPE_VALID, static_cast<Src>(1));
-    if (SrcLimits::is_iec559) {
-      TEST_EXPECTED_RANGE(TYPE_UNDERFLOW, SrcLimits::max() * -1);
-      TEST_EXPECTED_RANGE(TYPE_VALID, static_cast<Src>(-1));
-      TEST_EXPECTED_RANGE(TYPE_OVERFLOW, SrcLimits::infinity());
-      TEST_EXPECTED_RANGE(TYPE_UNDERFLOW, SrcLimits::infinity() * -1);
-      TEST_EXPECTED_RANGE(TYPE_INVALID, SrcLimits::quiet_NaN());
-    } else if (SrcLimits::is_signed) {
-      TEST_EXPECTED_RANGE(TYPE_UNDERFLOW, SrcLimits::min());
-      TEST_EXPECTED_RANGE(TYPE_VALID, static_cast<Src>(-1));
-    } else {
-      TEST_EXPECTED_RANGE(TYPE_VALID, SrcLimits::min());
-    }
-  }
-};
-
-template <typename Dst, typename Src>
-struct TestNumericConversion<Dst, Src, SIGN_TO_UNSIGN_WIDEN_OR_EQUAL> {
-  static void Test(const char *dst, const char *src, int line) {
-    typedef std::numeric_limits<Src> SrcLimits;
-    typedef std::numeric_limits<Dst> DstLimits;
-    COMPILE_ASSERT(sizeof(Dst) >= sizeof(Src),
-                   destination_must_be_equal_or_wider_than_source);
-    COMPILE_ASSERT(SrcLimits::is_signed, source_must_be_signed);
-    COMPILE_ASSERT(!DstLimits::is_signed, destination_must_be_unsigned);
-
-    TEST_EXPECTED_RANGE(TYPE_UNDERFLOW, SrcLimits::min());
-    TEST_EXPECTED_RANGE(TYPE_VALID, SrcLimits::max());
-    TEST_EXPECTED_RANGE(TYPE_VALID, static_cast<Src>(1));
-    TEST_EXPECTED_RANGE(TYPE_UNDERFLOW, static_cast<Src>(-1));
-  }
-};
-
-template <typename Dst, typename Src>
-struct TestNumericConversion<Dst, Src, SIGN_TO_UNSIGN_NARROW> {
-  static void Test(const char *dst, const char *src, int line) {
-    typedef std::numeric_limits<Src> SrcLimits;
-    typedef std::numeric_limits<Dst> DstLimits;
-    COMPILE_ASSERT((DstLimits::is_integer && SrcLimits::is_iec559) ||
-                   (sizeof(Dst) < sizeof(Src)),
-      destination_must_be_narrower_than_source);
-    COMPILE_ASSERT(SrcLimits::is_signed, source_must_be_signed);
-    COMPILE_ASSERT(!DstLimits::is_signed, destination_must_be_unsigned);
-
-    TEST_EXPECTED_RANGE(TYPE_OVERFLOW, SrcLimits::max());
-    TEST_EXPECTED_RANGE(TYPE_VALID, static_cast<Src>(1));
-    TEST_EXPECTED_RANGE(TYPE_UNDERFLOW, static_cast<Src>(-1));
-    if (SrcLimits::is_iec559) {
-      TEST_EXPECTED_RANGE(TYPE_UNDERFLOW, SrcLimits::max() * -1);
-      TEST_EXPECTED_RANGE(TYPE_OVERFLOW, SrcLimits::infinity());
-      TEST_EXPECTED_RANGE(TYPE_UNDERFLOW, SrcLimits::infinity() * -1);
-      TEST_EXPECTED_RANGE(TYPE_INVALID, SrcLimits::quiet_NaN());
-    } else {
-      TEST_EXPECTED_RANGE(TYPE_UNDERFLOW, SrcLimits::min());
-    }
-  }
-};
-
-template <typename Dst, typename Src>
-struct TestNumericConversion<Dst, Src, UNSIGN_TO_SIGN_NARROW_OR_EQUAL> {
-  static void Test(const char *dst, const char *src, int line) {
-    typedef std::numeric_limits<Src> SrcLimits;
-    typedef std::numeric_limits<Dst> DstLimits;
-    COMPILE_ASSERT(sizeof(Dst) <= sizeof(Src),
-                   destination_must_be_narrower_or_equal_to_source);
-    COMPILE_ASSERT(!SrcLimits::is_signed, source_must_be_unsigned);
-    COMPILE_ASSERT(DstLimits::is_signed, destination_must_be_signed);
-
-    TEST_EXPECTED_RANGE(TYPE_VALID, SrcLimits::min());
-    TEST_EXPECTED_RANGE(TYPE_OVERFLOW, SrcLimits::max());
-    TEST_EXPECTED_RANGE(TYPE_VALID, static_cast<Src>(1));
-  }
-};
-
-// Helper macro to wrap displaying the conversion types and line numbers
-#define TEST_NUMERIC_CONVERSION(d, s, t) \
-  TestNumericConversion<d, s, t>::Test(#d, #s, __LINE__)
-
-TEST(SafeNumerics, IntMinConversions) {
-  TEST_NUMERIC_CONVERSION(int8_t, int8_t, SIGN_PRESERVING_VALUE_PRESERVING);
-  TEST_NUMERIC_CONVERSION(uint8_t, uint8_t, SIGN_PRESERVING_VALUE_PRESERVING);
-
-  TEST_NUMERIC_CONVERSION(int8_t, int, SIGN_PRESERVING_NARROW);
-  TEST_NUMERIC_CONVERSION(uint8_t, unsigned int, SIGN_PRESERVING_NARROW);
-  TEST_NUMERIC_CONVERSION(int8_t, float, SIGN_PRESERVING_NARROW);
-
-  TEST_NUMERIC_CONVERSION(uint8_t, int8_t, SIGN_TO_UNSIGN_WIDEN_OR_EQUAL);
-
-  TEST_NUMERIC_CONVERSION(uint8_t, int, SIGN_TO_UNSIGN_NARROW);
-  TEST_NUMERIC_CONVERSION(uint8_t, intmax_t, SIGN_TO_UNSIGN_NARROW);
-  TEST_NUMERIC_CONVERSION(uint8_t, float, SIGN_TO_UNSIGN_NARROW);
-
-  TEST_NUMERIC_CONVERSION(int8_t, unsigned int, UNSIGN_TO_SIGN_NARROW_OR_EQUAL);
-  TEST_NUMERIC_CONVERSION(int8_t, uintmax_t, UNSIGN_TO_SIGN_NARROW_OR_EQUAL);
-}
-
-TEST(SafeNumerics, IntConversions) {
-  TEST_NUMERIC_CONVERSION(int, int, SIGN_PRESERVING_VALUE_PRESERVING);
-  TEST_NUMERIC_CONVERSION(unsigned int, unsigned int,
-                          SIGN_PRESERVING_VALUE_PRESERVING);
-  TEST_NUMERIC_CONVERSION(int, int8_t, SIGN_PRESERVING_VALUE_PRESERVING);
-  TEST_NUMERIC_CONVERSION(unsigned int, uint8_t,
-                          SIGN_PRESERVING_VALUE_PRESERVING);
-  TEST_NUMERIC_CONVERSION(int, uint8_t, SIGN_PRESERVING_VALUE_PRESERVING);
-
-  TEST_NUMERIC_CONVERSION(int, intmax_t, SIGN_PRESERVING_NARROW);
-  TEST_NUMERIC_CONVERSION(unsigned int, uintmax_t, SIGN_PRESERVING_NARROW);
-  TEST_NUMERIC_CONVERSION(int, float, SIGN_PRESERVING_NARROW);
-  TEST_NUMERIC_CONVERSION(int, double, SIGN_PRESERVING_NARROW);
-
-  TEST_NUMERIC_CONVERSION(unsigned int, int, SIGN_TO_UNSIGN_WIDEN_OR_EQUAL);
-  TEST_NUMERIC_CONVERSION(unsigned int, int8_t, SIGN_TO_UNSIGN_WIDEN_OR_EQUAL);
-
-  TEST_NUMERIC_CONVERSION(unsigned int, intmax_t, SIGN_TO_UNSIGN_NARROW);
-  TEST_NUMERIC_CONVERSION(unsigned int, float, SIGN_TO_UNSIGN_NARROW);
-  TEST_NUMERIC_CONVERSION(unsigned int, double, SIGN_TO_UNSIGN_NARROW);
-
-  TEST_NUMERIC_CONVERSION(int, unsigned int, UNSIGN_TO_SIGN_NARROW_OR_EQUAL);
-  TEST_NUMERIC_CONVERSION(int, uintmax_t, UNSIGN_TO_SIGN_NARROW_OR_EQUAL);
-}
-
-TEST(SafeNumerics, IntMaxConversions) {
-  TEST_NUMERIC_CONVERSION(intmax_t, intmax_t, SIGN_PRESERVING_VALUE_PRESERVING);
-  TEST_NUMERIC_CONVERSION(uintmax_t, uintmax_t,
-                          SIGN_PRESERVING_VALUE_PRESERVING);
-  TEST_NUMERIC_CONVERSION(intmax_t, int, SIGN_PRESERVING_VALUE_PRESERVING);
-  TEST_NUMERIC_CONVERSION(uintmax_t, unsigned int,
-                          SIGN_PRESERVING_VALUE_PRESERVING);
-  TEST_NUMERIC_CONVERSION(intmax_t, unsigned int,
-                          SIGN_PRESERVING_VALUE_PRESERVING);
-  TEST_NUMERIC_CONVERSION(intmax_t, uint8_t, SIGN_PRESERVING_VALUE_PRESERVING);
-
-  TEST_NUMERIC_CONVERSION(intmax_t, float, SIGN_PRESERVING_NARROW);
-  TEST_NUMERIC_CONVERSION(intmax_t, double, SIGN_PRESERVING_NARROW);
-
-  TEST_NUMERIC_CONVERSION(uintmax_t, int, SIGN_TO_UNSIGN_WIDEN_OR_EQUAL);
-  TEST_NUMERIC_CONVERSION(uintmax_t, int8_t, SIGN_TO_UNSIGN_WIDEN_OR_EQUAL);
-
-  TEST_NUMERIC_CONVERSION(uintmax_t, float, SIGN_TO_UNSIGN_NARROW);
-  TEST_NUMERIC_CONVERSION(uintmax_t, double, SIGN_TO_UNSIGN_NARROW);
-
-  TEST_NUMERIC_CONVERSION(intmax_t, uintmax_t, UNSIGN_TO_SIGN_NARROW_OR_EQUAL);
-}
-
-TEST(SafeNumerics, FloatConversions) {
-  TEST_NUMERIC_CONVERSION(float, intmax_t, SIGN_PRESERVING_VALUE_PRESERVING);
-  TEST_NUMERIC_CONVERSION(float, uintmax_t,
-                          SIGN_PRESERVING_VALUE_PRESERVING);
-  TEST_NUMERIC_CONVERSION(float, int, SIGN_PRESERVING_VALUE_PRESERVING);
-  TEST_NUMERIC_CONVERSION(float, unsigned int,
-                          SIGN_PRESERVING_VALUE_PRESERVING);
-
-  TEST_NUMERIC_CONVERSION(float, double, SIGN_PRESERVING_NARROW);
-}
-
-TEST(SafeNumerics, DoubleConversions) {
-  TEST_NUMERIC_CONVERSION(double, intmax_t, SIGN_PRESERVING_VALUE_PRESERVING);
-  TEST_NUMERIC_CONVERSION(double, uintmax_t,
-                          SIGN_PRESERVING_VALUE_PRESERVING);
-  TEST_NUMERIC_CONVERSION(double, int, SIGN_PRESERVING_VALUE_PRESERVING);
-  TEST_NUMERIC_CONVERSION(double, unsigned int,
-                          SIGN_PRESERVING_VALUE_PRESERVING);
-}
-
-TEST(SafeNumerics, SizeTConversions) {
-  TEST_NUMERIC_CONVERSION(size_t, int, SIGN_TO_UNSIGN_WIDEN_OR_EQUAL);
-  TEST_NUMERIC_CONVERSION(int, size_t, UNSIGN_TO_SIGN_NARROW_OR_EQUAL);
-}
-
-TEST(SafeNumerics, CastTests) {
-// MSVC catches and warns that we're forcing saturation in these tests.
-// Since that's intentional, we need to shut this warning off.
-#if defined(COMPILER_MSVC)
-#pragma warning(disable : 4756)
-#endif
-
-  int small_positive = 1;
-  int small_negative = -1;
-  double double_small = 1.0;
-  double double_large = std::numeric_limits<double>::max();
-  double double_infinity = std::numeric_limits<float>::infinity();
-
-  // Just test that the cast compiles, since the other tests cover logic.
-  EXPECT_EQ(0, base::checked_numeric_cast<int>(static_cast<size_t>(0)));
-
-  // Test various saturation corner cases.
-  EXPECT_EQ(saturated_cast<int>(small_negative),
-            static_cast<int>(small_negative));
-  EXPECT_EQ(saturated_cast<int>(small_positive),
-            static_cast<int>(small_positive));
-  EXPECT_EQ(saturated_cast<unsigned>(small_negative),
-            static_cast<unsigned>(0));
-  EXPECT_EQ(saturated_cast<int>(double_small),
-            static_cast<int>(double_small));
-  EXPECT_EQ(saturated_cast<int>(double_large),
-            std::numeric_limits<int>::max());
-  EXPECT_EQ(saturated_cast<float>(double_large), double_infinity);
-  EXPECT_EQ(saturated_cast<float>(-double_large), -double_infinity);
-}
-
-}  // namespace internal
-}  // namespace base