base/numerics/safe_numerics_unittest.cc

   1 // Copyright 2013 The Chromium Authors. All rights reserved.
   2 // Use of this source code is governed by a BSD-style license that can be
   3 // found in the LICENSE file.
   4
   5 #if defined(COMPILER_MSVC) && defined(ARCH_CPU_32_BITS)
   6 #include <mmintrin.h>
   7 #endif
   8 #include <stdint.h>
   9
  10 #include <limits>
  11
  12 #include "base/compiler_specific.h"
  13 #include "base/numerics/safe_conversions.h"
  14 #include "base/numerics/safe_math.h"
  15 #include "base/template_util.h"
  16 #include "testing/gtest/include/gtest/gtest.h"
  17
  18 using std::numeric_limits;
  19 using base::CheckedNumeric;
  20 using base::checked_cast;
  21 using base::saturated_cast;
  22 using base::internal::MaxExponent;
  23 using base::internal::RANGE_VALID;
  24 using base::internal::RANGE_INVALID;
  25 using base::internal::RANGE_OVERFLOW;
  26 using base::internal::RANGE_UNDERFLOW;
  27 using base::enable_if;
  28
  29 // These tests deliberately cause arithmetic overflows. If the compiler is
  30 // aggressive enough, it can const fold these overflows. Disable warnings about
  31 // overflows for const expressions.
  32 #if defined(OS_WIN)
  33 #pragma warning(disable:4756)
  34 #endif
  35
  36 // Helper macros to wrap displaying the conversion types and line numbers.
  37 #define TEST_EXPECTED_VALIDITY(expected, actual)                           \
  38   EXPECT_EQ(expected, CheckedNumeric<Dst>(actual).validity())              \
  39       << "Result test: Value " << +(actual).ValueUnsafe() << " as " << dst \
  40       << " on line " << line;
  41
  42 #define TEST_EXPECTED_VALUE(expected, actual)                                \
  43   EXPECT_EQ(static_cast<Dst>(expected),                                      \
  44             CheckedNumeric<Dst>(actual).ValueUnsafe())                       \
  45       << "Result test: Value " << +((actual).ValueUnsafe()) << " as " << dst \
  46       << " on line " << line;
  47
  48 // Signed integer arithmetic.
  49 template <typename Dst>
  50 static void TestSpecializedArithmetic(
  51     const char* dst,
  52     int line,
  53     typename enable_if<
  54         numeric_limits<Dst>::is_integer&& numeric_limits<Dst>::is_signed,
  55         int>::type = 0) {
  56   typedef numeric_limits<Dst> DstLimits;
  57   TEST_EXPECTED_VALIDITY(RANGE_OVERFLOW,
  58                          -CheckedNumeric<Dst>(DstLimits::min()));
  59   TEST_EXPECTED_VALIDITY(RANGE_OVERFLOW,
  60                          CheckedNumeric<Dst>(DstLimits::min()).Abs());
  61   TEST_EXPECTED_VALUE(1, CheckedNumeric<Dst>(-1).Abs());
  62
  63   TEST_EXPECTED_VALIDITY(RANGE_VALID,
  64                          CheckedNumeric<Dst>(DstLimits::max()) + -1);
  65   TEST_EXPECTED_VALIDITY(RANGE_UNDERFLOW,
  66                          CheckedNumeric<Dst>(DstLimits::min()) + -1);
  67   TEST_EXPECTED_VALIDITY(
  68       RANGE_UNDERFLOW,
  69       CheckedNumeric<Dst>(-DstLimits::max()) + -DstLimits::max());
  70
  71   TEST_EXPECTED_VALIDITY(RANGE_UNDERFLOW,
  72                          CheckedNumeric<Dst>(DstLimits::min()) - 1);
  73   TEST_EXPECTED_VALIDITY(RANGE_VALID,
  74                          CheckedNumeric<Dst>(DstLimits::min()) - -1);
  75   TEST_EXPECTED_VALIDITY(
  76       RANGE_OVERFLOW,
  77       CheckedNumeric<Dst>(DstLimits::max()) - -DstLimits::max());
  78   TEST_EXPECTED_VALIDITY(
  79       RANGE_UNDERFLOW,
  80       CheckedNumeric<Dst>(-DstLimits::max()) - DstLimits::max());
  81
  82   TEST_EXPECTED_VALIDITY(RANGE_UNDERFLOW,
  83                          CheckedNumeric<Dst>(DstLimits::min()) * 2);
  84
  85   TEST_EXPECTED_VALIDITY(RANGE_OVERFLOW,
  86                          CheckedNumeric<Dst>(DstLimits::min()) / -1);
  87   TEST_EXPECTED_VALUE(0, CheckedNumeric<Dst>(-1) / 2);
  88
  89   // Modulus is legal only for integers.
  90   TEST_EXPECTED_VALUE(0, CheckedNumeric<Dst>() % 1);
  91   TEST_EXPECTED_VALUE(0, CheckedNumeric<Dst>(1) % 1);
  92   TEST_EXPECTED_VALUE(-1, CheckedNumeric<Dst>(-1) % 2);
  93   TEST_EXPECTED_VALIDITY(RANGE_INVALID, CheckedNumeric<Dst>(-1) % -2);
  94   TEST_EXPECTED_VALUE(0, CheckedNumeric<Dst>(DstLimits::min()) % 2);
  95   TEST_EXPECTED_VALUE(1, CheckedNumeric<Dst>(DstLimits::max()) % 2);
  96   // Test all the different modulus combinations.
  97   TEST_EXPECTED_VALUE(0, CheckedNumeric<Dst>(1) % CheckedNumeric<Dst>(1));
  98   TEST_EXPECTED_VALUE(0, 1 % CheckedNumeric<Dst>(1));
  99   TEST_EXPECTED_VALUE(0, CheckedNumeric<Dst>(1) % 1);
 100   CheckedNumeric<Dst> checked_dst = 1;
 101   TEST_EXPECTED_VALUE(0, checked_dst %= 1);
 102 }
 103
 104 // Unsigned integer arithmetic.
 105 template <typename Dst>
 106 static void TestSpecializedArithmetic(
 107     const char* dst,
 108     int line,
 109     typename enable_if<
 110         numeric_limits<Dst>::is_integer && !numeric_limits<Dst>::is_signed,
 111         int>::type = 0) {
 112   typedef numeric_limits<Dst> DstLimits;
 113   TEST_EXPECTED_VALIDITY(RANGE_VALID, -CheckedNumeric<Dst>(DstLimits::min()));
 114   TEST_EXPECTED_VALIDITY(RANGE_VALID,
 115                          CheckedNumeric<Dst>(DstLimits::min()).Abs());
 116   TEST_EXPECTED_VALIDITY(RANGE_UNDERFLOW,
 117                          CheckedNumeric<Dst>(DstLimits::min()) + -1);
 118   TEST_EXPECTED_VALIDITY(RANGE_UNDERFLOW,
 119                          CheckedNumeric<Dst>(DstLimits::min()) - 1);
 120   TEST_EXPECTED_VALUE(0, CheckedNumeric<Dst>(DstLimits::min()) * 2);
 121   TEST_EXPECTED_VALUE(0, CheckedNumeric<Dst>(1) / 2);
 122
 123   // Modulus is legal only for integers.
 124   TEST_EXPECTED_VALUE(0, CheckedNumeric<Dst>() % 1);
 125   TEST_EXPECTED_VALUE(0, CheckedNumeric<Dst>(1) % 1);
 126   TEST_EXPECTED_VALUE(1, CheckedNumeric<Dst>(1) % 2);
 127   TEST_EXPECTED_VALUE(0, CheckedNumeric<Dst>(DstLimits::min()) % 2);
 128   TEST_EXPECTED_VALUE(1, CheckedNumeric<Dst>(DstLimits::max()) % 2);
 129   // Test all the different modulus combinations.
 130   TEST_EXPECTED_VALUE(0, CheckedNumeric<Dst>(1) % CheckedNumeric<Dst>(1));
 131   TEST_EXPECTED_VALUE(0, 1 % CheckedNumeric<Dst>(1));
 132   TEST_EXPECTED_VALUE(0, CheckedNumeric<Dst>(1) % 1);
 133   CheckedNumeric<Dst> checked_dst = 1;
 134   TEST_EXPECTED_VALUE(0, checked_dst %= 1);
 135 }
 136
 137 // Floating point arithmetic.
 138 template <typename Dst>
 139 void TestSpecializedArithmetic(
 140     const char* dst,
 141     int line,
 142     typename enable_if<numeric_limits<Dst>::is_iec559, int>::type = 0) {
 143   typedef numeric_limits<Dst> DstLimits;
 144   TEST_EXPECTED_VALIDITY(RANGE_VALID, -CheckedNumeric<Dst>(DstLimits::min()));
 145
 146   TEST_EXPECTED_VALIDITY(RANGE_VALID,
 147                          CheckedNumeric<Dst>(DstLimits::min()).Abs());
 148   TEST_EXPECTED_VALUE(1, CheckedNumeric<Dst>(-1).Abs());
 149
 150   TEST_EXPECTED_VALIDITY(RANGE_VALID,
 151                          CheckedNumeric<Dst>(DstLimits::min()) + -1);
 152   TEST_EXPECTED_VALIDITY(RANGE_VALID,
 153                          CheckedNumeric<Dst>(DstLimits::max()) + 1);
 154   TEST_EXPECTED_VALIDITY(
 155       RANGE_UNDERFLOW,
 156       CheckedNumeric<Dst>(-DstLimits::max()) + -DstLimits::max());
 157
 158   TEST_EXPECTED_VALIDITY(
 159       RANGE_OVERFLOW,
 160       CheckedNumeric<Dst>(DstLimits::max()) - -DstLimits::max());
 161   TEST_EXPECTED_VALIDITY(
 162       RANGE_UNDERFLOW,
 163       CheckedNumeric<Dst>(-DstLimits::max()) - DstLimits::max());
 164
 165   TEST_EXPECTED_VALIDITY(RANGE_VALID,
 166                          CheckedNumeric<Dst>(DstLimits::min()) * 2);
 167
 168   TEST_EXPECTED_VALUE(-0.5, CheckedNumeric<Dst>(-1.0) / 2);
 169   EXPECT_EQ(static_cast<Dst>(1.0), CheckedNumeric<Dst>(1.0).ValueFloating());
 170 }
 171
 172 // Generic arithmetic tests.
 173 template <typename Dst>
 174 static void TestArithmetic(const char* dst, int line) {
 175   typedef numeric_limits<Dst> DstLimits;
 176
 177   EXPECT_EQ(true, CheckedNumeric<Dst>().IsValid());
 178   EXPECT_EQ(false,
 179             CheckedNumeric<Dst>(CheckedNumeric<Dst>(DstLimits::max()) *
 180                                 DstLimits::max()).IsValid());
 181   EXPECT_EQ(static_cast<Dst>(0), CheckedNumeric<Dst>().ValueOrDie());
 182   EXPECT_EQ(static_cast<Dst>(0), CheckedNumeric<Dst>().ValueOrDefault(1));
 183   EXPECT_EQ(static_cast<Dst>(1),
 184             CheckedNumeric<Dst>(CheckedNumeric<Dst>(DstLimits::max()) *
 185                                 DstLimits::max()).ValueOrDefault(1));
 186
 187   // Test the operator combinations.
 188   TEST_EXPECTED_VALUE(2, CheckedNumeric<Dst>(1) + CheckedNumeric<Dst>(1));
 189   TEST_EXPECTED_VALUE(0, CheckedNumeric<Dst>(1) - CheckedNumeric<Dst>(1));
 190   TEST_EXPECTED_VALUE(1, CheckedNumeric<Dst>(1) * CheckedNumeric<Dst>(1));
 191   TEST_EXPECTED_VALUE(1, CheckedNumeric<Dst>(1) / CheckedNumeric<Dst>(1));
 192   TEST_EXPECTED_VALUE(2, 1 + CheckedNumeric<Dst>(1));
 193   TEST_EXPECTED_VALUE(0, 1 - CheckedNumeric<Dst>(1));
 194   TEST_EXPECTED_VALUE(1, 1 * CheckedNumeric<Dst>(1));
 195   TEST_EXPECTED_VALUE(1, 1 / CheckedNumeric<Dst>(1));
 196   TEST_EXPECTED_VALUE(2, CheckedNumeric<Dst>(1) + 1);
 197   TEST_EXPECTED_VALUE(0, CheckedNumeric<Dst>(1) - 1);
 198   TEST_EXPECTED_VALUE(1, CheckedNumeric<Dst>(1) * 1);
 199   TEST_EXPECTED_VALUE(1, CheckedNumeric<Dst>(1) / 1);
 200   CheckedNumeric<Dst> checked_dst = 1;
 201   TEST_EXPECTED_VALUE(2, checked_dst += 1);
 202   checked_dst = 1;
 203   TEST_EXPECTED_VALUE(0, checked_dst -= 1);
 204   checked_dst = 1;
 205   TEST_EXPECTED_VALUE(1, checked_dst *= 1);
 206   checked_dst = 1;
 207   TEST_EXPECTED_VALUE(1, checked_dst /= 1);
 208
 209   // Generic negation.
 210   TEST_EXPECTED_VALUE(0, -CheckedNumeric<Dst>());
 211   TEST_EXPECTED_VALUE(-1, -CheckedNumeric<Dst>(1));
 212   TEST_EXPECTED_VALUE(1, -CheckedNumeric<Dst>(-1));
 213   TEST_EXPECTED_VALUE(static_cast<Dst>(DstLimits::max() * -1),
 214                       -CheckedNumeric<Dst>(DstLimits::max()));
 215
 216   // Generic absolute value.
 217   TEST_EXPECTED_VALUE(0, CheckedNumeric<Dst>().Abs());
 218   TEST_EXPECTED_VALUE(1, CheckedNumeric<Dst>(1).Abs());
 219   TEST_EXPECTED_VALUE(DstLimits::max(),
 220                       CheckedNumeric<Dst>(DstLimits::max()).Abs());
 221
 222   // Generic addition.
 223   TEST_EXPECTED_VALUE(1, (CheckedNumeric<Dst>() + 1));
 224   TEST_EXPECTED_VALUE(2, (CheckedNumeric<Dst>(1) + 1));
 225   TEST_EXPECTED_VALUE(0, (CheckedNumeric<Dst>(-1) + 1));
 226   TEST_EXPECTED_VALIDITY(RANGE_VALID,
 227                          CheckedNumeric<Dst>(DstLimits::min()) + 1);
 228   TEST_EXPECTED_VALIDITY(
 229       RANGE_OVERFLOW, CheckedNumeric<Dst>(DstLimits::max()) + DstLimits::max());
 230
 231   // Generic subtraction.
 232   TEST_EXPECTED_VALUE(-1, (CheckedNumeric<Dst>() - 1));
 233   TEST_EXPECTED_VALUE(0, (CheckedNumeric<Dst>(1) - 1));
 234   TEST_EXPECTED_VALUE(-2, (CheckedNumeric<Dst>(-1) - 1));
 235   TEST_EXPECTED_VALIDITY(RANGE_VALID,
 236                          CheckedNumeric<Dst>(DstLimits::max()) - 1);
 237
 238   // Generic multiplication.
 239   TEST_EXPECTED_VALUE(0, (CheckedNumeric<Dst>() * 1));
 240   TEST_EXPECTED_VALUE(1, (CheckedNumeric<Dst>(1) * 1));
 241   TEST_EXPECTED_VALUE(-2, (CheckedNumeric<Dst>(-1) * 2));
 242   TEST_EXPECTED_VALIDITY(
 243       RANGE_OVERFLOW, CheckedNumeric<Dst>(DstLimits::max()) * DstLimits::max());
 244
 245   // Generic division.
 246   TEST_EXPECTED_VALUE(0, CheckedNumeric<Dst>() / 1);
 247   TEST_EXPECTED_VALUE(1, CheckedNumeric<Dst>(1) / 1);
 248   TEST_EXPECTED_VALUE(DstLimits::min() / 2,
 249                       CheckedNumeric<Dst>(DstLimits::min()) / 2);
 250   TEST_EXPECTED_VALUE(DstLimits::max() / 2,
 251                       CheckedNumeric<Dst>(DstLimits::max()) / 2);
 252
 253   TestSpecializedArithmetic<Dst>(dst, line);
 254 }
 255
 256 // Helper macro to wrap displaying the conversion types and line numbers.
 257 #define TEST_ARITHMETIC(Dst) TestArithmetic<Dst>(#Dst, __LINE__)
 258
 259 TEST(SafeNumerics, SignedIntegerMath) {
 260   TEST_ARITHMETIC(int8_t);
 261   TEST_ARITHMETIC(int);
 262   TEST_ARITHMETIC(intptr_t);
 263   TEST_ARITHMETIC(intmax_t);
 264 }
 265
 266 TEST(SafeNumerics, UnsignedIntegerMath) {
 267   TEST_ARITHMETIC(uint8_t);
 268   TEST_ARITHMETIC(unsigned int);
 269   TEST_ARITHMETIC(uintptr_t);
 270   TEST_ARITHMETIC(uintmax_t);
 271 }
 272
 273 TEST(SafeNumerics, FloatingPointMath) {
 274   TEST_ARITHMETIC(float);
 275   TEST_ARITHMETIC(double);
 276 }
 277
 278 // Enumerates the five different conversions types we need to test.
 279 enum NumericConversionType {
 280   SIGN_PRESERVING_VALUE_PRESERVING,
 281   SIGN_PRESERVING_NARROW,
 282   SIGN_TO_UNSIGN_WIDEN_OR_EQUAL,
 283   SIGN_TO_UNSIGN_NARROW,
 284   UNSIGN_TO_SIGN_NARROW_OR_EQUAL,
 285 };
 286
 287 // Template covering the different conversion tests.
 288 template <typename Dst, typename Src, NumericConversionType conversion>
 289 struct TestNumericConversion {};
 290
 291 // EXPECT_EQ wrappers providing specific detail on test failures.
 292 #define TEST_EXPECTED_RANGE(expected, actual)                                  \
 293   EXPECT_EQ(expected, base::internal::DstRangeRelationToSrcRange<Dst>(actual)) \
 294       << "Conversion test: " << src << " value " << actual << " to " << dst    \
 295       << " on line " << line;
 296
 297 template <typename Dst, typename Src>
 298 struct TestNumericConversion<Dst, Src, SIGN_PRESERVING_VALUE_PRESERVING> {
 299   static void Test(const char *dst, const char *src, int line) {
 300     typedef numeric_limits<Src> SrcLimits;
 301     typedef numeric_limits<Dst> DstLimits;
 302                    // Integral to floating.
 303     static_assert((DstLimits::is_iec559 && SrcLimits::is_integer) ||
 304                   // Not floating to integral and...
 305                   (!(DstLimits::is_integer && SrcLimits::is_iec559) &&
 306                    // Same sign, same numeric, source is narrower or same.
 307                    ((SrcLimits::is_signed == DstLimits::is_signed &&
 308                     sizeof(Dst) >= sizeof(Src)) ||
 309                    // Or signed destination and source is smaller
 310                     (DstLimits::is_signed && sizeof(Dst) > sizeof(Src)))),
 311                   "Comparison must be sign preserving and value preserving");
 312
 313     const CheckedNumeric<Dst> checked_dst = SrcLimits::max();
 314     ;
 315     TEST_EXPECTED_VALIDITY(RANGE_VALID, checked_dst);
 316     if (MaxExponent<Dst>::value > MaxExponent<Src>::value) {
 317       if (MaxExponent<Dst>::value >= MaxExponent<Src>::value * 2 - 1) {
 318         // At least twice larger type.
 319         TEST_EXPECTED_VALIDITY(RANGE_VALID, SrcLimits::max() * checked_dst);
 320
 321       } else {  // Larger, but not at least twice as large.
 322         TEST_EXPECTED_VALIDITY(RANGE_OVERFLOW, SrcLimits::max() * checked_dst);
 323         TEST_EXPECTED_VALIDITY(RANGE_VALID, checked_dst + 1);
 324       }
 325     } else {  // Same width type.
 326       TEST_EXPECTED_VALIDITY(RANGE_OVERFLOW, checked_dst + 1);
 327     }
 328
 329     TEST_EXPECTED_RANGE(RANGE_VALID, SrcLimits::max());
 330     TEST_EXPECTED_RANGE(RANGE_VALID, static_cast<Src>(1));
 331     if (SrcLimits::is_iec559) {
 332       TEST_EXPECTED_RANGE(RANGE_VALID, SrcLimits::max() * static_cast<Src>(-1));
 333       TEST_EXPECTED_RANGE(RANGE_OVERFLOW, SrcLimits::infinity());
 334       TEST_EXPECTED_RANGE(RANGE_UNDERFLOW, SrcLimits::infinity() * -1);
 335       TEST_EXPECTED_RANGE(RANGE_INVALID, SrcLimits::quiet_NaN());
 336     } else if (numeric_limits<Src>::is_signed) {
 337       TEST_EXPECTED_RANGE(RANGE_VALID, static_cast<Src>(-1));
 338       TEST_EXPECTED_RANGE(RANGE_VALID, SrcLimits::min());
 339     }
 340   }
 341 };
 342
 343 template <typename Dst, typename Src>
 344 struct TestNumericConversion<Dst, Src, SIGN_PRESERVING_NARROW> {
 345   static void Test(const char *dst, const char *src, int line) {
 346     typedef numeric_limits<Src> SrcLimits;
 347     typedef numeric_limits<Dst> DstLimits;
 348     static_assert(SrcLimits::is_signed == DstLimits::is_signed,
 349                   "Destination and source sign must be the same");
 350     static_assert(sizeof(Dst) < sizeof(Src) ||
 351                    (DstLimits::is_integer && SrcLimits::is_iec559),
 352                   "Destination must be narrower than source");
 353
 354     const CheckedNumeric<Dst> checked_dst;
 355     TEST_EXPECTED_VALIDITY(RANGE_OVERFLOW, checked_dst + SrcLimits::max());
 356     TEST_EXPECTED_VALUE(1, checked_dst + static_cast<Src>(1));
 357     TEST_EXPECTED_VALIDITY(RANGE_UNDERFLOW, checked_dst - SrcLimits::max());
 358
 359     TEST_EXPECTED_RANGE(RANGE_OVERFLOW, SrcLimits::max());
 360     TEST_EXPECTED_RANGE(RANGE_VALID, static_cast<Src>(1));
 361     if (SrcLimits::is_iec559) {
 362       TEST_EXPECTED_RANGE(RANGE_UNDERFLOW, SrcLimits::max() * -1);
 363       TEST_EXPECTED_RANGE(RANGE_VALID, static_cast<Src>(-1));
 364       TEST_EXPECTED_RANGE(RANGE_OVERFLOW, SrcLimits::infinity());
 365       TEST_EXPECTED_RANGE(RANGE_UNDERFLOW, SrcLimits::infinity() * -1);
 366       TEST_EXPECTED_RANGE(RANGE_INVALID, SrcLimits::quiet_NaN());
 367     } else if (SrcLimits::is_signed) {
 368       TEST_EXPECTED_VALUE(-1, checked_dst - static_cast<Src>(1));
 369       TEST_EXPECTED_RANGE(RANGE_UNDERFLOW, SrcLimits::min());
 370       TEST_EXPECTED_RANGE(RANGE_VALID, static_cast<Src>(-1));
 371     } else {
 372       TEST_EXPECTED_VALIDITY(RANGE_INVALID, checked_dst - static_cast<Src>(1));
 373       TEST_EXPECTED_RANGE(RANGE_VALID, SrcLimits::min());
 374     }
 375   }
 376 };
 377
 378 template <typename Dst, typename Src>
 379 struct TestNumericConversion<Dst, Src, SIGN_TO_UNSIGN_WIDEN_OR_EQUAL> {
 380   static void Test(const char *dst, const char *src, int line) {
 381     typedef numeric_limits<Src> SrcLimits;
 382     typedef numeric_limits<Dst> DstLimits;
 383     static_assert(sizeof(Dst) >= sizeof(Src),
 384                   "Destination must be equal or wider than source.");
 385     static_assert(SrcLimits::is_signed, "Source must be signed");
 386     static_assert(!DstLimits::is_signed, "Destination must be unsigned");
 387
 388     const CheckedNumeric<Dst> checked_dst;
 389     TEST_EXPECTED_VALUE(SrcLimits::max(), checked_dst + SrcLimits::max());
 390     TEST_EXPECTED_VALIDITY(RANGE_UNDERFLOW, checked_dst + static_cast<Src>(-1));
 391     TEST_EXPECTED_VALIDITY(RANGE_UNDERFLOW, checked_dst + -SrcLimits::max());
 392
 393     TEST_EXPECTED_RANGE(RANGE_UNDERFLOW, SrcLimits::min());
 394     TEST_EXPECTED_RANGE(RANGE_VALID, SrcLimits::max());
 395     TEST_EXPECTED_RANGE(RANGE_VALID, static_cast<Src>(1));
 396     TEST_EXPECTED_RANGE(RANGE_UNDERFLOW, static_cast<Src>(-1));
 397   }
 398 };
 399
 400 template <typename Dst, typename Src>
 401 struct TestNumericConversion<Dst, Src, SIGN_TO_UNSIGN_NARROW> {
 402   static void Test(const char *dst, const char *src, int line) {
 403     typedef numeric_limits<Src> SrcLimits;
 404     typedef numeric_limits<Dst> DstLimits;
 405     static_assert((DstLimits::is_integer && SrcLimits::is_iec559) ||
 406                    (sizeof(Dst) < sizeof(Src)),
 407                   "Destination must be narrower than source.");
 408     static_assert(SrcLimits::is_signed, "Source must be signed.");
 409     static_assert(!DstLimits::is_signed, "Destination must be unsigned.");
 410
 411     const CheckedNumeric<Dst> checked_dst;
 412     TEST_EXPECTED_VALUE(1, checked_dst + static_cast<Src>(1));
 413     TEST_EXPECTED_VALIDITY(RANGE_OVERFLOW, checked_dst + SrcLimits::max());
 414     TEST_EXPECTED_VALIDITY(RANGE_UNDERFLOW, checked_dst + static_cast<Src>(-1));
 415     TEST_EXPECTED_VALIDITY(RANGE_UNDERFLOW, checked_dst + -SrcLimits::max());
 416
 417     TEST_EXPECTED_RANGE(RANGE_OVERFLOW, SrcLimits::max());
 418     TEST_EXPECTED_RANGE(RANGE_VALID, static_cast<Src>(1));
 419     TEST_EXPECTED_RANGE(RANGE_UNDERFLOW, static_cast<Src>(-1));
 420     if (SrcLimits::is_iec559) {
 421       TEST_EXPECTED_RANGE(RANGE_UNDERFLOW, SrcLimits::max() * -1);
 422       TEST_EXPECTED_RANGE(RANGE_OVERFLOW, SrcLimits::infinity());
 423       TEST_EXPECTED_RANGE(RANGE_UNDERFLOW, SrcLimits::infinity() * -1);
 424       TEST_EXPECTED_RANGE(RANGE_INVALID, SrcLimits::quiet_NaN());
 425     } else {
 426       TEST_EXPECTED_RANGE(RANGE_UNDERFLOW, SrcLimits::min());
 427     }
 428   }
 429 };
 430
 431 template <typename Dst, typename Src>
 432 struct TestNumericConversion<Dst, Src, UNSIGN_TO_SIGN_NARROW_OR_EQUAL> {
 433   static void Test(const char *dst, const char *src, int line) {
 434     typedef numeric_limits<Src> SrcLimits;
 435     typedef numeric_limits<Dst> DstLimits;
 436     static_assert(sizeof(Dst) <= sizeof(Src),
 437                   "Destination must be narrower or equal to source.");
 438     static_assert(!SrcLimits::is_signed, "Source must be unsigned.");
 439     static_assert(DstLimits::is_signed, "Destination must be signed.");
 440
 441     const CheckedNumeric<Dst> checked_dst;
 442     TEST_EXPECTED_VALUE(1, checked_dst + static_cast<Src>(1));
 443     TEST_EXPECTED_VALIDITY(RANGE_OVERFLOW, checked_dst + SrcLimits::max());
 444     TEST_EXPECTED_VALUE(SrcLimits::min(), checked_dst + SrcLimits::min());
 445
 446     TEST_EXPECTED_RANGE(RANGE_VALID, SrcLimits::min());
 447     TEST_EXPECTED_RANGE(RANGE_OVERFLOW, SrcLimits::max());
 448     TEST_EXPECTED_RANGE(RANGE_VALID, static_cast<Src>(1));
 449   }
 450 };
 451
 452 // Helper macro to wrap displaying the conversion types and line numbers
 453 #define TEST_NUMERIC_CONVERSION(d, s, t) \
 454   TestNumericConversion<d, s, t>::Test(#d, #s, __LINE__)
 455
 456 TEST(SafeNumerics, IntMinOperations) {
 457   TEST_NUMERIC_CONVERSION(int8_t, int8_t, SIGN_PRESERVING_VALUE_PRESERVING);
 458   TEST_NUMERIC_CONVERSION(uint8_t, uint8_t, SIGN_PRESERVING_VALUE_PRESERVING);
 459
 460   TEST_NUMERIC_CONVERSION(int8_t, int, SIGN_PRESERVING_NARROW);
 461   TEST_NUMERIC_CONVERSION(uint8_t, unsigned int, SIGN_PRESERVING_NARROW);
 462   TEST_NUMERIC_CONVERSION(int8_t, float, SIGN_PRESERVING_NARROW);
 463
 464   TEST_NUMERIC_CONVERSION(uint8_t, int8_t, SIGN_TO_UNSIGN_WIDEN_OR_EQUAL);
 465
 466   TEST_NUMERIC_CONVERSION(uint8_t, int, SIGN_TO_UNSIGN_NARROW);
 467   TEST_NUMERIC_CONVERSION(uint8_t, intmax_t, SIGN_TO_UNSIGN_NARROW);
 468   TEST_NUMERIC_CONVERSION(uint8_t, float, SIGN_TO_UNSIGN_NARROW);
 469
 470   TEST_NUMERIC_CONVERSION(int8_t, unsigned int, UNSIGN_TO_SIGN_NARROW_OR_EQUAL);
 471   TEST_NUMERIC_CONVERSION(int8_t, uintmax_t, UNSIGN_TO_SIGN_NARROW_OR_EQUAL);
 472 }
 473
 474 TEST(SafeNumerics, IntOperations) {
 475   TEST_NUMERIC_CONVERSION(int, int, SIGN_PRESERVING_VALUE_PRESERVING);
 476   TEST_NUMERIC_CONVERSION(unsigned int, unsigned int,
 477                           SIGN_PRESERVING_VALUE_PRESERVING);
 478   TEST_NUMERIC_CONVERSION(int, int8_t, SIGN_PRESERVING_VALUE_PRESERVING);
 479   TEST_NUMERIC_CONVERSION(unsigned int, uint8_t,
 480                           SIGN_PRESERVING_VALUE_PRESERVING);
 481   TEST_NUMERIC_CONVERSION(int, uint8_t, SIGN_PRESERVING_VALUE_PRESERVING);
 482
 483   TEST_NUMERIC_CONVERSION(int, intmax_t, SIGN_PRESERVING_NARROW);
 484   TEST_NUMERIC_CONVERSION(unsigned int, uintmax_t, SIGN_PRESERVING_NARROW);
 485   TEST_NUMERIC_CONVERSION(int, float, SIGN_PRESERVING_NARROW);
 486   TEST_NUMERIC_CONVERSION(int, double, SIGN_PRESERVING_NARROW);
 487
 488   TEST_NUMERIC_CONVERSION(unsigned int, int, SIGN_TO_UNSIGN_WIDEN_OR_EQUAL);
 489   TEST_NUMERIC_CONVERSION(unsigned int, int8_t, SIGN_TO_UNSIGN_WIDEN_OR_EQUAL);
 490
 491   TEST_NUMERIC_CONVERSION(unsigned int, intmax_t, SIGN_TO_UNSIGN_NARROW);
 492   TEST_NUMERIC_CONVERSION(unsigned int, float, SIGN_TO_UNSIGN_NARROW);
 493   TEST_NUMERIC_CONVERSION(unsigned int, double, SIGN_TO_UNSIGN_NARROW);
 494
 495   TEST_NUMERIC_CONVERSION(int, unsigned int, UNSIGN_TO_SIGN_NARROW_OR_EQUAL);
 496   TEST_NUMERIC_CONVERSION(int, uintmax_t, UNSIGN_TO_SIGN_NARROW_OR_EQUAL);
 497 }
 498
 499 TEST(SafeNumerics, IntMaxOperations) {
 500   TEST_NUMERIC_CONVERSION(intmax_t, intmax_t, SIGN_PRESERVING_VALUE_PRESERVING);
 501   TEST_NUMERIC_CONVERSION(uintmax_t, uintmax_t,
 502                           SIGN_PRESERVING_VALUE_PRESERVING);
 503   TEST_NUMERIC_CONVERSION(intmax_t, int, SIGN_PRESERVING_VALUE_PRESERVING);
 504   TEST_NUMERIC_CONVERSION(uintmax_t, unsigned int,
 505                           SIGN_PRESERVING_VALUE_PRESERVING);
 506   TEST_NUMERIC_CONVERSION(intmax_t, unsigned int,
 507                           SIGN_PRESERVING_VALUE_PRESERVING);
 508   TEST_NUMERIC_CONVERSION(intmax_t, uint8_t, SIGN_PRESERVING_VALUE_PRESERVING);
 509
 510   TEST_NUMERIC_CONVERSION(intmax_t, float, SIGN_PRESERVING_NARROW);
 511   TEST_NUMERIC_CONVERSION(intmax_t, double, SIGN_PRESERVING_NARROW);
 512
 513   TEST_NUMERIC_CONVERSION(uintmax_t, int, SIGN_TO_UNSIGN_WIDEN_OR_EQUAL);
 514   TEST_NUMERIC_CONVERSION(uintmax_t, int8_t, SIGN_TO_UNSIGN_WIDEN_OR_EQUAL);
 515
 516   TEST_NUMERIC_CONVERSION(uintmax_t, float, SIGN_TO_UNSIGN_NARROW);
 517   TEST_NUMERIC_CONVERSION(uintmax_t, double, SIGN_TO_UNSIGN_NARROW);
 518
 519   TEST_NUMERIC_CONVERSION(intmax_t, uintmax_t, UNSIGN_TO_SIGN_NARROW_OR_EQUAL);
 520 }
 521
 522 TEST(SafeNumerics, FloatOperations) {
 523   TEST_NUMERIC_CONVERSION(float, intmax_t, SIGN_PRESERVING_VALUE_PRESERVING);
 524   TEST_NUMERIC_CONVERSION(float, uintmax_t,
 525                           SIGN_PRESERVING_VALUE_PRESERVING);
 526   TEST_NUMERIC_CONVERSION(float, int, SIGN_PRESERVING_VALUE_PRESERVING);
 527   TEST_NUMERIC_CONVERSION(float, unsigned int,
 528                           SIGN_PRESERVING_VALUE_PRESERVING);
 529
 530   TEST_NUMERIC_CONVERSION(float, double, SIGN_PRESERVING_NARROW);
 531 }
 532
 533 TEST(SafeNumerics, DoubleOperations) {
 534   TEST_NUMERIC_CONVERSION(double, intmax_t, SIGN_PRESERVING_VALUE_PRESERVING);
 535   TEST_NUMERIC_CONVERSION(double, uintmax_t,
 536                           SIGN_PRESERVING_VALUE_PRESERVING);
 537   TEST_NUMERIC_CONVERSION(double, int, SIGN_PRESERVING_VALUE_PRESERVING);
 538   TEST_NUMERIC_CONVERSION(double, unsigned int,
 539                           SIGN_PRESERVING_VALUE_PRESERVING);
 540 }
 541
 542 TEST(SafeNumerics, SizeTOperations) {
 543   TEST_NUMERIC_CONVERSION(size_t, int, SIGN_TO_UNSIGN_WIDEN_OR_EQUAL);
 544   TEST_NUMERIC_CONVERSION(int, size_t, UNSIGN_TO_SIGN_NARROW_OR_EQUAL);
 545 }
 546
 547 TEST(SafeNumerics, CastTests) {
 548 // MSVC catches and warns that we're forcing saturation in these tests.
 549 // Since that's intentional, we need to shut this warning off.
 550 #if defined(COMPILER_MSVC)
 551 #pragma warning(disable : 4756)
 552 #endif
 553
 554   int small_positive = 1;
 555   int small_negative = -1;
 556   double double_small = 1.0;
 557   double double_large = numeric_limits<double>::max();
 558   double double_infinity = numeric_limits<float>::infinity();
 559
 560   // Just test that the cast compiles, since the other tests cover logic.
 561   EXPECT_EQ(0, checked_cast<int>(static_cast<size_t>(0)));
 562
 563   // Test various saturation corner cases.
 564   EXPECT_EQ(saturated_cast<int>(small_negative),
 565             static_cast<int>(small_negative));
 566   EXPECT_EQ(saturated_cast<int>(small_positive),
 567             static_cast<int>(small_positive));
 568   EXPECT_EQ(saturated_cast<unsigned>(small_negative),
 569             static_cast<unsigned>(0));
 570   EXPECT_EQ(saturated_cast<int>(double_small),
 571             static_cast<int>(double_small));
 572   EXPECT_EQ(saturated_cast<int>(double_large), numeric_limits<int>::max());
 573   EXPECT_EQ(saturated_cast<float>(double_large), double_infinity);
 574   EXPECT_EQ(saturated_cast<float>(-double_large), -double_infinity);
 575 }
 576