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::SizeT;
  22 using base::StrictNumeric;
  23 using base::saturated_cast;
  24 using base::strict_cast;
  25 using base::internal::MaxExponent;
  26 using base::internal::RANGE_VALID;
  27 using base::internal::RANGE_INVALID;
  28 using base::internal::RANGE_OVERFLOW;
  29 using base::internal::RANGE_UNDERFLOW;
  30 using base::enable_if;
  31
  32 // These tests deliberately cause arithmetic overflows. If the compiler is
  33 // aggressive enough, it can const fold these overflows. Disable warnings about
  34 // overflows for const expressions.
  35 #if defined(OS_WIN)
  36 #pragma warning(disable:4756)
  37 #endif
  38
  39 // Helper macros to wrap displaying the conversion types and line numbers.
  40 #define TEST_EXPECTED_VALIDITY(expected, actual)                           \
  41   EXPECT_EQ(expected, CheckedNumeric<Dst>(actual).validity())              \
  42       << "Result test: Value " << +(actual).ValueUnsafe() << " as " << dst \
  43       << " on line " << line;
  44
  45 #define TEST_EXPECTED_VALUE(expected, actual)                                \
  46   EXPECT_EQ(static_cast<Dst>(expected),                                      \
  47             CheckedNumeric<Dst>(actual).ValueUnsafe())                       \
  48       << "Result test: Value " << +((actual).ValueUnsafe()) << " as " << dst \
  49       << " on line " << line;
  50
  51 // Signed integer arithmetic.
  52 template <typename Dst>
  53 static void TestSpecializedArithmetic(
  54     const char* dst,
  55     int line,
  56     typename enable_if<
  57         numeric_limits<Dst>::is_integer&& numeric_limits<Dst>::is_signed,
  58         int>::type = 0) {
  59   typedef numeric_limits<Dst> DstLimits;
  60   TEST_EXPECTED_VALIDITY(RANGE_OVERFLOW,
  61                          -CheckedNumeric<Dst>(DstLimits::min()));
  62   TEST_EXPECTED_VALIDITY(RANGE_OVERFLOW,
  63                          CheckedNumeric<Dst>(DstLimits::min()).Abs());
  64   TEST_EXPECTED_VALUE(1, CheckedNumeric<Dst>(-1).Abs());
  65
  66   TEST_EXPECTED_VALIDITY(RANGE_VALID,
  67                          CheckedNumeric<Dst>(DstLimits::max()) + -1);
  68   TEST_EXPECTED_VALIDITY(RANGE_UNDERFLOW,
  69                          CheckedNumeric<Dst>(DstLimits::min()) + -1);
  70   TEST_EXPECTED_VALIDITY(
  71       RANGE_UNDERFLOW,
  72       CheckedNumeric<Dst>(-DstLimits::max()) + -DstLimits::max());
  73
  74   TEST_EXPECTED_VALIDITY(RANGE_UNDERFLOW,
  75                          CheckedNumeric<Dst>(DstLimits::min()) - 1);
  76   TEST_EXPECTED_VALIDITY(RANGE_VALID,
  77                          CheckedNumeric<Dst>(DstLimits::min()) - -1);
  78   TEST_EXPECTED_VALIDITY(
  79       RANGE_OVERFLOW,
  80       CheckedNumeric<Dst>(DstLimits::max()) - -DstLimits::max());
  81   TEST_EXPECTED_VALIDITY(
  82       RANGE_UNDERFLOW,
  83       CheckedNumeric<Dst>(-DstLimits::max()) - DstLimits::max());
  84
  85   TEST_EXPECTED_VALIDITY(RANGE_UNDERFLOW,
  86                          CheckedNumeric<Dst>(DstLimits::min()) * 2);
  87
  88   TEST_EXPECTED_VALIDITY(RANGE_OVERFLOW,
  89                          CheckedNumeric<Dst>(DstLimits::min()) / -1);
  90   TEST_EXPECTED_VALUE(0, CheckedNumeric<Dst>(-1) / 2);
  91
  92   // Modulus is legal only for integers.
  93   TEST_EXPECTED_VALUE(0, CheckedNumeric<Dst>() % 1);
  94   TEST_EXPECTED_VALUE(0, CheckedNumeric<Dst>(1) % 1);
  95   TEST_EXPECTED_VALUE(-1, CheckedNumeric<Dst>(-1) % 2);
  96   TEST_EXPECTED_VALIDITY(RANGE_INVALID, CheckedNumeric<Dst>(-1) % -2);
  97   TEST_EXPECTED_VALUE(0, CheckedNumeric<Dst>(DstLimits::min()) % 2);
  98   TEST_EXPECTED_VALUE(1, CheckedNumeric<Dst>(DstLimits::max()) % 2);
  99   // Test all the different modulus combinations.
 100   TEST_EXPECTED_VALUE(0, CheckedNumeric<Dst>(1) % CheckedNumeric<Dst>(1));
 101   TEST_EXPECTED_VALUE(0, 1 % CheckedNumeric<Dst>(1));
 102   TEST_EXPECTED_VALUE(0, CheckedNumeric<Dst>(1) % 1);
 103   CheckedNumeric<Dst> checked_dst = 1;
 104   TEST_EXPECTED_VALUE(0, checked_dst %= 1);
 105 }
 106
 107 // Unsigned integer arithmetic.
 108 template <typename Dst>
 109 static void TestSpecializedArithmetic(
 110     const char* dst,
 111     int line,
 112     typename enable_if<
 113         numeric_limits<Dst>::is_integer && !numeric_limits<Dst>::is_signed,
 114         int>::type = 0) {
 115   typedef numeric_limits<Dst> DstLimits;
 116   TEST_EXPECTED_VALIDITY(RANGE_VALID, -CheckedNumeric<Dst>(DstLimits::min()));
 117   TEST_EXPECTED_VALIDITY(RANGE_VALID,
 118                          CheckedNumeric<Dst>(DstLimits::min()).Abs());
 119   TEST_EXPECTED_VALIDITY(RANGE_UNDERFLOW,
 120                          CheckedNumeric<Dst>(DstLimits::min()) + -1);
 121   TEST_EXPECTED_VALIDITY(RANGE_UNDERFLOW,
 122                          CheckedNumeric<Dst>(DstLimits::min()) - 1);
 123   TEST_EXPECTED_VALUE(0, CheckedNumeric<Dst>(DstLimits::min()) * 2);
 124   TEST_EXPECTED_VALUE(0, CheckedNumeric<Dst>(1) / 2);
 125
 126   // Modulus is legal only for integers.
 127   TEST_EXPECTED_VALUE(0, CheckedNumeric<Dst>() % 1);
 128   TEST_EXPECTED_VALUE(0, CheckedNumeric<Dst>(1) % 1);
 129   TEST_EXPECTED_VALUE(1, CheckedNumeric<Dst>(1) % 2);
 130   TEST_EXPECTED_VALUE(0, CheckedNumeric<Dst>(DstLimits::min()) % 2);
 131   TEST_EXPECTED_VALUE(1, CheckedNumeric<Dst>(DstLimits::max()) % 2);
 132   // Test all the different modulus combinations.
 133   TEST_EXPECTED_VALUE(0, CheckedNumeric<Dst>(1) % CheckedNumeric<Dst>(1));
 134   TEST_EXPECTED_VALUE(0, 1 % CheckedNumeric<Dst>(1));
 135   TEST_EXPECTED_VALUE(0, CheckedNumeric<Dst>(1) % 1);
 136   CheckedNumeric<Dst> checked_dst = 1;
 137   TEST_EXPECTED_VALUE(0, checked_dst %= 1);
 138 }
 139
 140 // Floating point arithmetic.
 141 template <typename Dst>
 142 void TestSpecializedArithmetic(
 143     const char* dst,
 144     int line,
 145     typename enable_if<numeric_limits<Dst>::is_iec559, int>::type = 0) {
 146   typedef numeric_limits<Dst> DstLimits;
 147   TEST_EXPECTED_VALIDITY(RANGE_VALID, -CheckedNumeric<Dst>(DstLimits::min()));
 148
 149   TEST_EXPECTED_VALIDITY(RANGE_VALID,
 150                          CheckedNumeric<Dst>(DstLimits::min()).Abs());
 151   TEST_EXPECTED_VALUE(1, CheckedNumeric<Dst>(-1).Abs());
 152
 153   TEST_EXPECTED_VALIDITY(RANGE_VALID,
 154                          CheckedNumeric<Dst>(DstLimits::min()) + -1);
 155   TEST_EXPECTED_VALIDITY(RANGE_VALID,
 156                          CheckedNumeric<Dst>(DstLimits::max()) + 1);
 157   TEST_EXPECTED_VALIDITY(
 158       RANGE_UNDERFLOW,
 159       CheckedNumeric<Dst>(-DstLimits::max()) + -DstLimits::max());
 160
 161   TEST_EXPECTED_VALIDITY(
 162       RANGE_OVERFLOW,
 163       CheckedNumeric<Dst>(DstLimits::max()) - -DstLimits::max());
 164   TEST_EXPECTED_VALIDITY(
 165       RANGE_UNDERFLOW,
 166       CheckedNumeric<Dst>(-DstLimits::max()) - DstLimits::max());
 167
 168   TEST_EXPECTED_VALIDITY(RANGE_VALID,
 169                          CheckedNumeric<Dst>(DstLimits::min()) * 2);
 170
 171   TEST_EXPECTED_VALUE(-0.5, CheckedNumeric<Dst>(-1.0) / 2);
 172   EXPECT_EQ(static_cast<Dst>(1.0), CheckedNumeric<Dst>(1.0).ValueFloating());
 173 }
 174
 175 // Generic arithmetic tests.
 176 template <typename Dst>
 177 static void TestArithmetic(const char* dst, int line) {
 178   typedef numeric_limits<Dst> DstLimits;
 179
 180   EXPECT_EQ(true, CheckedNumeric<Dst>().IsValid());
 181   EXPECT_EQ(false,
 182             CheckedNumeric<Dst>(CheckedNumeric<Dst>(DstLimits::max()) *
 183                                 DstLimits::max()).IsValid());
 184   EXPECT_EQ(static_cast<Dst>(0), CheckedNumeric<Dst>().ValueOrDie());
 185   EXPECT_EQ(static_cast<Dst>(0), CheckedNumeric<Dst>().ValueOrDefault(1));
 186   EXPECT_EQ(static_cast<Dst>(1),
 187             CheckedNumeric<Dst>(CheckedNumeric<Dst>(DstLimits::max()) *
 188                                 DstLimits::max()).ValueOrDefault(1));
 189
 190   // Test the operator combinations.
 191   TEST_EXPECTED_VALUE(2, CheckedNumeric<Dst>(1) + CheckedNumeric<Dst>(1));
 192   TEST_EXPECTED_VALUE(0, CheckedNumeric<Dst>(1) - CheckedNumeric<Dst>(1));
 193   TEST_EXPECTED_VALUE(1, CheckedNumeric<Dst>(1) * CheckedNumeric<Dst>(1));
 194   TEST_EXPECTED_VALUE(1, CheckedNumeric<Dst>(1) / CheckedNumeric<Dst>(1));
 195   TEST_EXPECTED_VALUE(2, 1 + CheckedNumeric<Dst>(1));
 196   TEST_EXPECTED_VALUE(0, 1 - CheckedNumeric<Dst>(1));
 197   TEST_EXPECTED_VALUE(1, 1 * CheckedNumeric<Dst>(1));
 198   TEST_EXPECTED_VALUE(1, 1 / CheckedNumeric<Dst>(1));
 199   TEST_EXPECTED_VALUE(2, CheckedNumeric<Dst>(1) + 1);
 200   TEST_EXPECTED_VALUE(0, CheckedNumeric<Dst>(1) - 1);
 201   TEST_EXPECTED_VALUE(1, CheckedNumeric<Dst>(1) * 1);
 202   TEST_EXPECTED_VALUE(1, CheckedNumeric<Dst>(1) / 1);
 203   CheckedNumeric<Dst> checked_dst = 1;
 204   TEST_EXPECTED_VALUE(2, checked_dst += 1);
 205   checked_dst = 1;
 206   TEST_EXPECTED_VALUE(0, checked_dst -= 1);
 207   checked_dst = 1;
 208   TEST_EXPECTED_VALUE(1, checked_dst *= 1);
 209   checked_dst = 1;
 210   TEST_EXPECTED_VALUE(1, checked_dst /= 1);
 211
 212   // Generic negation.
 213   TEST_EXPECTED_VALUE(0, -CheckedNumeric<Dst>());
 214   TEST_EXPECTED_VALUE(-1, -CheckedNumeric<Dst>(1));
 215   TEST_EXPECTED_VALUE(1, -CheckedNumeric<Dst>(-1));
 216   TEST_EXPECTED_VALUE(static_cast<Dst>(DstLimits::max() * -1),
 217                       -CheckedNumeric<Dst>(DstLimits::max()));
 218
 219   // Generic absolute value.
 220   TEST_EXPECTED_VALUE(0, CheckedNumeric<Dst>().Abs());
 221   TEST_EXPECTED_VALUE(1, CheckedNumeric<Dst>(1).Abs());
 222   TEST_EXPECTED_VALUE(DstLimits::max(),
 223                       CheckedNumeric<Dst>(DstLimits::max()).Abs());
 224
 225   // Generic addition.
 226   TEST_EXPECTED_VALUE(1, (CheckedNumeric<Dst>() + 1));
 227   TEST_EXPECTED_VALUE(2, (CheckedNumeric<Dst>(1) + 1));
 228   TEST_EXPECTED_VALUE(0, (CheckedNumeric<Dst>(-1) + 1));
 229   TEST_EXPECTED_VALIDITY(RANGE_VALID,
 230                          CheckedNumeric<Dst>(DstLimits::min()) + 1);
 231   TEST_EXPECTED_VALIDITY(
 232       RANGE_OVERFLOW, CheckedNumeric<Dst>(DstLimits::max()) + DstLimits::max());
 233
 234   // Generic subtraction.
 235   TEST_EXPECTED_VALUE(-1, (CheckedNumeric<Dst>() - 1));
 236   TEST_EXPECTED_VALUE(0, (CheckedNumeric<Dst>(1) - 1));
 237   TEST_EXPECTED_VALUE(-2, (CheckedNumeric<Dst>(-1) - 1));
 238   TEST_EXPECTED_VALIDITY(RANGE_VALID,
 239                          CheckedNumeric<Dst>(DstLimits::max()) - 1);
 240
 241   // Generic multiplication.
 242   TEST_EXPECTED_VALUE(0, (CheckedNumeric<Dst>() * 1));
 243   TEST_EXPECTED_VALUE(1, (CheckedNumeric<Dst>(1) * 1));
 244   TEST_EXPECTED_VALUE(-2, (CheckedNumeric<Dst>(-1) * 2));
 245   TEST_EXPECTED_VALUE(0, (CheckedNumeric<Dst>(0) * 0));
 246   TEST_EXPECTED_VALUE(0, (CheckedNumeric<Dst>(-1) * 0));
 247   TEST_EXPECTED_VALUE(0, (CheckedNumeric<Dst>(0) * -1));
 248   TEST_EXPECTED_VALIDITY(
 249       RANGE_OVERFLOW, CheckedNumeric<Dst>(DstLimits::max()) * DstLimits::max());
 250
 251   // Generic division.
 252   TEST_EXPECTED_VALUE(0, CheckedNumeric<Dst>() / 1);
 253   TEST_EXPECTED_VALUE(1, CheckedNumeric<Dst>(1) / 1);
 254   TEST_EXPECTED_VALUE(DstLimits::min() / 2,
 255                       CheckedNumeric<Dst>(DstLimits::min()) / 2);
 256   TEST_EXPECTED_VALUE(DstLimits::max() / 2,
 257                       CheckedNumeric<Dst>(DstLimits::max()) / 2);
 258
 259   TestSpecializedArithmetic<Dst>(dst, line);
 260 }
 261
 262 // Helper macro to wrap displaying the conversion types and line numbers.
 263 #define TEST_ARITHMETIC(Dst) TestArithmetic<Dst>(#Dst, __LINE__)
 264
 265 TEST(SafeNumerics, SignedIntegerMath) {
 266   TEST_ARITHMETIC(int8_t);
 267   TEST_ARITHMETIC(int);
 268   TEST_ARITHMETIC(intptr_t);
 269   TEST_ARITHMETIC(intmax_t);
 270 }
 271
 272 TEST(SafeNumerics, UnsignedIntegerMath) {
 273   TEST_ARITHMETIC(uint8_t);
 274   TEST_ARITHMETIC(unsigned int);
 275   TEST_ARITHMETIC(uintptr_t);
 276   TEST_ARITHMETIC(uintmax_t);
 277 }
 278
 279 TEST(SafeNumerics, FloatingPointMath) {
 280   TEST_ARITHMETIC(float);
 281   TEST_ARITHMETIC(double);
 282 }
 283
 284 // Enumerates the five different conversions types we need to test.
 285 enum NumericConversionType {
 286   SIGN_PRESERVING_VALUE_PRESERVING,
 287   SIGN_PRESERVING_NARROW,
 288   SIGN_TO_UNSIGN_WIDEN_OR_EQUAL,
 289   SIGN_TO_UNSIGN_NARROW,
 290   UNSIGN_TO_SIGN_NARROW_OR_EQUAL,
 291 };
 292
 293 // Template covering the different conversion tests.
 294 template <typename Dst, typename Src, NumericConversionType conversion>
 295 struct TestNumericConversion {};
 296
 297 // EXPECT_EQ wrappers providing specific detail on test failures.
 298 #define TEST_EXPECTED_RANGE(expected, actual)                                  \
 299   EXPECT_EQ(expected, base::internal::DstRangeRelationToSrcRange<Dst>(actual)) \
 300       << "Conversion test: " << src << " value " << actual << " to " << dst    \
 301       << " on line " << line;
 302
 303 template <typename Dst, typename Src>
 304 struct TestNumericConversion<Dst, Src, SIGN_PRESERVING_VALUE_PRESERVING> {
 305   static void Test(const char *dst, const char *src, int line) {
 306     typedef numeric_limits<Src> SrcLimits;
 307     typedef numeric_limits<Dst> DstLimits;
 308                    // Integral to floating.
 309     static_assert((DstLimits::is_iec559 && SrcLimits::is_integer) ||
 310                   // Not floating to integral and...
 311                   (!(DstLimits::is_integer && SrcLimits::is_iec559) &&
 312                    // Same sign, same numeric, source is narrower or same.
 313                    ((SrcLimits::is_signed == DstLimits::is_signed &&
 314                     sizeof(Dst) >= sizeof(Src)) ||
 315                    // Or signed destination and source is smaller
 316                     (DstLimits::is_signed && sizeof(Dst) > sizeof(Src)))),
 317                   "Comparison must be sign preserving and value preserving");
 318
 319     const CheckedNumeric<Dst> checked_dst = SrcLimits::max();
 320     ;
 321     TEST_EXPECTED_VALIDITY(RANGE_VALID, checked_dst);
 322     if (MaxExponent<Dst>::value > MaxExponent<Src>::value) {
 323       if (MaxExponent<Dst>::value >= MaxExponent<Src>::value * 2 - 1) {
 324         // At least twice larger type.
 325         TEST_EXPECTED_VALIDITY(RANGE_VALID, SrcLimits::max() * checked_dst);
 326
 327       } else {  // Larger, but not at least twice as large.
 328         TEST_EXPECTED_VALIDITY(RANGE_OVERFLOW, SrcLimits::max() * checked_dst);
 329         TEST_EXPECTED_VALIDITY(RANGE_VALID, checked_dst + 1);
 330       }
 331     } else {  // Same width type.
 332       TEST_EXPECTED_VALIDITY(RANGE_OVERFLOW, checked_dst + 1);
 333     }
 334
 335     TEST_EXPECTED_RANGE(RANGE_VALID, SrcLimits::max());
 336     TEST_EXPECTED_RANGE(RANGE_VALID, static_cast<Src>(1));
 337     if (SrcLimits::is_iec559) {
 338       TEST_EXPECTED_RANGE(RANGE_VALID, SrcLimits::max() * static_cast<Src>(-1));
 339       TEST_EXPECTED_RANGE(RANGE_OVERFLOW, SrcLimits::infinity());
 340       TEST_EXPECTED_RANGE(RANGE_UNDERFLOW, SrcLimits::infinity() * -1);
 341       TEST_EXPECTED_RANGE(RANGE_INVALID, SrcLimits::quiet_NaN());
 342     } else if (numeric_limits<Src>::is_signed) {
 343       TEST_EXPECTED_RANGE(RANGE_VALID, static_cast<Src>(-1));
 344       TEST_EXPECTED_RANGE(RANGE_VALID, SrcLimits::min());
 345     }
 346   }
 347 };
 348
 349 template <typename Dst, typename Src>
 350 struct TestNumericConversion<Dst, Src, SIGN_PRESERVING_NARROW> {
 351   static void Test(const char *dst, const char *src, int line) {
 352     typedef numeric_limits<Src> SrcLimits;
 353     typedef numeric_limits<Dst> DstLimits;
 354     static_assert(SrcLimits::is_signed == DstLimits::is_signed,
 355                   "Destination and source sign must be the same");
 356     static_assert(sizeof(Dst) < sizeof(Src) ||
 357                    (DstLimits::is_integer && SrcLimits::is_iec559),
 358                   "Destination must be narrower than source");
 359
 360     const CheckedNumeric<Dst> checked_dst;
 361     TEST_EXPECTED_VALIDITY(RANGE_OVERFLOW, checked_dst + SrcLimits::max());
 362     TEST_EXPECTED_VALUE(1, checked_dst + static_cast<Src>(1));
 363     TEST_EXPECTED_VALIDITY(RANGE_UNDERFLOW, checked_dst - SrcLimits::max());
 364
 365     TEST_EXPECTED_RANGE(RANGE_OVERFLOW, SrcLimits::max());
 366     TEST_EXPECTED_RANGE(RANGE_VALID, static_cast<Src>(1));
 367     if (SrcLimits::is_iec559) {
 368       TEST_EXPECTED_RANGE(RANGE_UNDERFLOW, SrcLimits::max() * -1);
 369       TEST_EXPECTED_RANGE(RANGE_VALID, static_cast<Src>(-1));
 370       TEST_EXPECTED_RANGE(RANGE_OVERFLOW, SrcLimits::infinity());
 371       TEST_EXPECTED_RANGE(RANGE_UNDERFLOW, SrcLimits::infinity() * -1);
 372       TEST_EXPECTED_RANGE(RANGE_INVALID, SrcLimits::quiet_NaN());
 373     } else if (SrcLimits::is_signed) {
 374       TEST_EXPECTED_VALUE(-1, checked_dst - static_cast<Src>(1));
 375       TEST_EXPECTED_RANGE(RANGE_UNDERFLOW, SrcLimits::min());
 376       TEST_EXPECTED_RANGE(RANGE_VALID, static_cast<Src>(-1));
 377     } else {
 378       TEST_EXPECTED_VALIDITY(RANGE_INVALID, checked_dst - static_cast<Src>(1));
 379       TEST_EXPECTED_RANGE(RANGE_VALID, SrcLimits::min());
 380     }
 381   }
 382 };
 383
 384 template <typename Dst, typename Src>
 385 struct TestNumericConversion<Dst, Src, SIGN_TO_UNSIGN_WIDEN_OR_EQUAL> {
 386   static void Test(const char *dst, const char *src, int line) {
 387     typedef numeric_limits<Src> SrcLimits;
 388     typedef numeric_limits<Dst> DstLimits;
 389     static_assert(sizeof(Dst) >= sizeof(Src),
 390                   "Destination must be equal or wider than source.");
 391     static_assert(SrcLimits::is_signed, "Source must be signed");
 392     static_assert(!DstLimits::is_signed, "Destination must be unsigned");
 393
 394     const CheckedNumeric<Dst> checked_dst;
 395     TEST_EXPECTED_VALUE(SrcLimits::max(), checked_dst + SrcLimits::max());
 396     TEST_EXPECTED_VALIDITY(RANGE_UNDERFLOW, checked_dst + static_cast<Src>(-1));
 397     TEST_EXPECTED_VALIDITY(RANGE_UNDERFLOW, checked_dst + -SrcLimits::max());
 398
 399     TEST_EXPECTED_RANGE(RANGE_UNDERFLOW, SrcLimits::min());
 400     TEST_EXPECTED_RANGE(RANGE_VALID, SrcLimits::max());
 401     TEST_EXPECTED_RANGE(RANGE_VALID, static_cast<Src>(1));
 402     TEST_EXPECTED_RANGE(RANGE_UNDERFLOW, static_cast<Src>(-1));
 403   }
 404 };
 405
 406 template <typename Dst, typename Src>
 407 struct TestNumericConversion<Dst, Src, SIGN_TO_UNSIGN_NARROW> {
 408   static void Test(const char *dst, const char *src, int line) {
 409     typedef numeric_limits<Src> SrcLimits;
 410     typedef numeric_limits<Dst> DstLimits;
 411     static_assert((DstLimits::is_integer && SrcLimits::is_iec559) ||
 412                    (sizeof(Dst) < sizeof(Src)),
 413                   "Destination must be narrower than source.");
 414     static_assert(SrcLimits::is_signed, "Source must be signed.");
 415     static_assert(!DstLimits::is_signed, "Destination must be unsigned.");
 416
 417     const CheckedNumeric<Dst> checked_dst;
 418     TEST_EXPECTED_VALUE(1, checked_dst + static_cast<Src>(1));
 419     TEST_EXPECTED_VALIDITY(RANGE_OVERFLOW, checked_dst + SrcLimits::max());
 420     TEST_EXPECTED_VALIDITY(RANGE_UNDERFLOW, checked_dst + static_cast<Src>(-1));
 421     TEST_EXPECTED_VALIDITY(RANGE_UNDERFLOW, checked_dst + -SrcLimits::max());
 422
 423     TEST_EXPECTED_RANGE(RANGE_OVERFLOW, SrcLimits::max());
 424     TEST_EXPECTED_RANGE(RANGE_VALID, static_cast<Src>(1));
 425     TEST_EXPECTED_RANGE(RANGE_UNDERFLOW, static_cast<Src>(-1));
 426     if (SrcLimits::is_iec559) {
 427       TEST_EXPECTED_RANGE(RANGE_UNDERFLOW, SrcLimits::max() * -1);
 428       TEST_EXPECTED_RANGE(RANGE_OVERFLOW, SrcLimits::infinity());
 429       TEST_EXPECTED_RANGE(RANGE_UNDERFLOW, SrcLimits::infinity() * -1);
 430       TEST_EXPECTED_RANGE(RANGE_INVALID, SrcLimits::quiet_NaN());
 431     } else {
 432       TEST_EXPECTED_RANGE(RANGE_UNDERFLOW, SrcLimits::min());
 433     }
 434   }
 435 };
 436
 437 template <typename Dst, typename Src>
 438 struct TestNumericConversion<Dst, Src, UNSIGN_TO_SIGN_NARROW_OR_EQUAL> {
 439   static void Test(const char *dst, const char *src, int line) {
 440     typedef numeric_limits<Src> SrcLimits;
 441     typedef numeric_limits<Dst> DstLimits;
 442     static_assert(sizeof(Dst) <= sizeof(Src),
 443                   "Destination must be narrower or equal to source.");
 444     static_assert(!SrcLimits::is_signed, "Source must be unsigned.");
 445     static_assert(DstLimits::is_signed, "Destination must be signed.");
 446
 447     const CheckedNumeric<Dst> checked_dst;
 448     TEST_EXPECTED_VALUE(1, checked_dst + static_cast<Src>(1));
 449     TEST_EXPECTED_VALIDITY(RANGE_OVERFLOW, checked_dst + SrcLimits::max());
 450     TEST_EXPECTED_VALUE(SrcLimits::min(), checked_dst + SrcLimits::min());
 451
 452     TEST_EXPECTED_RANGE(RANGE_VALID, SrcLimits::min());
 453     TEST_EXPECTED_RANGE(RANGE_OVERFLOW, SrcLimits::max());
 454     TEST_EXPECTED_RANGE(RANGE_VALID, static_cast<Src>(1));
 455   }
 456 };
 457
 458 // Helper macro to wrap displaying the conversion types and line numbers
 459 #define TEST_NUMERIC_CONVERSION(d, s, t) \
 460   TestNumericConversion<d, s, t>::Test(#d, #s, __LINE__)
 461
 462 TEST(SafeNumerics, IntMinOperations) {
 463   TEST_NUMERIC_CONVERSION(int8_t, int8_t, SIGN_PRESERVING_VALUE_PRESERVING);
 464   TEST_NUMERIC_CONVERSION(uint8_t, uint8_t, SIGN_PRESERVING_VALUE_PRESERVING);
 465
 466   TEST_NUMERIC_CONVERSION(int8_t, int, SIGN_PRESERVING_NARROW);
 467   TEST_NUMERIC_CONVERSION(uint8_t, unsigned int, SIGN_PRESERVING_NARROW);
 468   TEST_NUMERIC_CONVERSION(int8_t, float, SIGN_PRESERVING_NARROW);
 469
 470   TEST_NUMERIC_CONVERSION(uint8_t, int8_t, SIGN_TO_UNSIGN_WIDEN_OR_EQUAL);
 471
 472   TEST_NUMERIC_CONVERSION(uint8_t, int, SIGN_TO_UNSIGN_NARROW);
 473   TEST_NUMERIC_CONVERSION(uint8_t, intmax_t, SIGN_TO_UNSIGN_NARROW);
 474   TEST_NUMERIC_CONVERSION(uint8_t, float, SIGN_TO_UNSIGN_NARROW);
 475
 476   TEST_NUMERIC_CONVERSION(int8_t, unsigned int, UNSIGN_TO_SIGN_NARROW_OR_EQUAL);
 477   TEST_NUMERIC_CONVERSION(int8_t, uintmax_t, UNSIGN_TO_SIGN_NARROW_OR_EQUAL);
 478 }
 479
 480 TEST(SafeNumerics, IntOperations) {
 481   TEST_NUMERIC_CONVERSION(int, int, SIGN_PRESERVING_VALUE_PRESERVING);
 482   TEST_NUMERIC_CONVERSION(unsigned int, unsigned int,
 483                           SIGN_PRESERVING_VALUE_PRESERVING);
 484   TEST_NUMERIC_CONVERSION(int, int8_t, SIGN_PRESERVING_VALUE_PRESERVING);
 485   TEST_NUMERIC_CONVERSION(unsigned int, uint8_t,
 486                           SIGN_PRESERVING_VALUE_PRESERVING);
 487   TEST_NUMERIC_CONVERSION(int, uint8_t, SIGN_PRESERVING_VALUE_PRESERVING);
 488
 489   TEST_NUMERIC_CONVERSION(int, intmax_t, SIGN_PRESERVING_NARROW);
 490   TEST_NUMERIC_CONVERSION(unsigned int, uintmax_t, SIGN_PRESERVING_NARROW);
 491   TEST_NUMERIC_CONVERSION(int, float, SIGN_PRESERVING_NARROW);
 492   TEST_NUMERIC_CONVERSION(int, double, SIGN_PRESERVING_NARROW);
 493
 494   TEST_NUMERIC_CONVERSION(unsigned int, int, SIGN_TO_UNSIGN_WIDEN_OR_EQUAL);
 495   TEST_NUMERIC_CONVERSION(unsigned int, int8_t, SIGN_TO_UNSIGN_WIDEN_OR_EQUAL);
 496
 497   TEST_NUMERIC_CONVERSION(unsigned int, intmax_t, SIGN_TO_UNSIGN_NARROW);
 498   TEST_NUMERIC_CONVERSION(unsigned int, float, SIGN_TO_UNSIGN_NARROW);
 499   TEST_NUMERIC_CONVERSION(unsigned int, double, SIGN_TO_UNSIGN_NARROW);
 500
 501   TEST_NUMERIC_CONVERSION(int, unsigned int, UNSIGN_TO_SIGN_NARROW_OR_EQUAL);
 502   TEST_NUMERIC_CONVERSION(int, uintmax_t, UNSIGN_TO_SIGN_NARROW_OR_EQUAL);
 503 }
 504
 505 TEST(SafeNumerics, IntMaxOperations) {
 506   TEST_NUMERIC_CONVERSION(intmax_t, intmax_t, SIGN_PRESERVING_VALUE_PRESERVING);
 507   TEST_NUMERIC_CONVERSION(uintmax_t, uintmax_t,
 508                           SIGN_PRESERVING_VALUE_PRESERVING);
 509   TEST_NUMERIC_CONVERSION(intmax_t, int, SIGN_PRESERVING_VALUE_PRESERVING);
 510   TEST_NUMERIC_CONVERSION(uintmax_t, unsigned int,
 511                           SIGN_PRESERVING_VALUE_PRESERVING);
 512   TEST_NUMERIC_CONVERSION(intmax_t, unsigned int,
 513                           SIGN_PRESERVING_VALUE_PRESERVING);
 514   TEST_NUMERIC_CONVERSION(intmax_t, uint8_t, SIGN_PRESERVING_VALUE_PRESERVING);
 515
 516   TEST_NUMERIC_CONVERSION(intmax_t, float, SIGN_PRESERVING_NARROW);
 517   TEST_NUMERIC_CONVERSION(intmax_t, double, SIGN_PRESERVING_NARROW);
 518
 519   TEST_NUMERIC_CONVERSION(uintmax_t, int, SIGN_TO_UNSIGN_WIDEN_OR_EQUAL);
 520   TEST_NUMERIC_CONVERSION(uintmax_t, int8_t, SIGN_TO_UNSIGN_WIDEN_OR_EQUAL);
 521
 522   TEST_NUMERIC_CONVERSION(uintmax_t, float, SIGN_TO_UNSIGN_NARROW);
 523   TEST_NUMERIC_CONVERSION(uintmax_t, double, SIGN_TO_UNSIGN_NARROW);
 524
 525   TEST_NUMERIC_CONVERSION(intmax_t, uintmax_t, UNSIGN_TO_SIGN_NARROW_OR_EQUAL);
 526 }
 527
 528 TEST(SafeNumerics, FloatOperations) {
 529   TEST_NUMERIC_CONVERSION(float, intmax_t, SIGN_PRESERVING_VALUE_PRESERVING);
 530   TEST_NUMERIC_CONVERSION(float, uintmax_t,
 531                           SIGN_PRESERVING_VALUE_PRESERVING);
 532   TEST_NUMERIC_CONVERSION(float, int, SIGN_PRESERVING_VALUE_PRESERVING);
 533   TEST_NUMERIC_CONVERSION(float, unsigned int,
 534                           SIGN_PRESERVING_VALUE_PRESERVING);
 535
 536   TEST_NUMERIC_CONVERSION(float, double, SIGN_PRESERVING_NARROW);
 537 }
 538
 539 TEST(SafeNumerics, DoubleOperations) {
 540   TEST_NUMERIC_CONVERSION(double, intmax_t, SIGN_PRESERVING_VALUE_PRESERVING);
 541   TEST_NUMERIC_CONVERSION(double, uintmax_t,
 542                           SIGN_PRESERVING_VALUE_PRESERVING);
 543   TEST_NUMERIC_CONVERSION(double, int, SIGN_PRESERVING_VALUE_PRESERVING);
 544   TEST_NUMERIC_CONVERSION(double, unsigned int,
 545                           SIGN_PRESERVING_VALUE_PRESERVING);
 546 }
 547
 548 TEST(SafeNumerics, SizeTOperations) {
 549   TEST_NUMERIC_CONVERSION(size_t, int, SIGN_TO_UNSIGN_WIDEN_OR_EQUAL);
 550   TEST_NUMERIC_CONVERSION(int, size_t, UNSIGN_TO_SIGN_NARROW_OR_EQUAL);
 551 }
 552
 553 TEST(SafeNumerics, CastTests) {
 554 // MSVC catches and warns that we're forcing saturation in these tests.
 555 // Since that's intentional, we need to shut this warning off.
 556 #if defined(COMPILER_MSVC)
 557 #pragma warning(disable : 4756)
 558 #endif
 559
 560   int small_positive = 1;
 561   int small_negative = -1;
 562   double double_small = 1.0;
 563   double double_large = numeric_limits<double>::max();
 564   double double_infinity = numeric_limits<float>::infinity();
 565   double double_large_int = numeric_limits<int>::max();
 566   double double_small_int = numeric_limits<int>::min();
 567
 568   // Just test that the casts compile, since the other tests cover logic.
 569   EXPECT_EQ(0, checked_cast<int>(static_cast<size_t>(0)));
 570   EXPECT_EQ(0, strict_cast<int>(static_cast<char>(0)));
 571   EXPECT_EQ(0, strict_cast<int>(static_cast<unsigned char>(0)));
 572   EXPECT_EQ(0U, strict_cast<unsigned>(static_cast<unsigned char>(0)));
 573   EXPECT_EQ(1ULL, static_cast<uint64_t>(StrictNumeric<size_t>(1U)));
 574   EXPECT_EQ(1ULL, static_cast<uint64_t>(SizeT(1U)));
 575   EXPECT_EQ(1U, static_cast<size_t>(StrictNumeric<unsigned>(1U)));
 576
 577   EXPECT_TRUE(CheckedNumeric<uint64_t>(StrictNumeric<unsigned>(1U)).IsValid());
 578   EXPECT_TRUE(CheckedNumeric<int>(StrictNumeric<unsigned>(1U)).IsValid());
 579   EXPECT_FALSE(CheckedNumeric<unsigned>(StrictNumeric<int>(-1)).IsValid());
 580
 581   // These casts and coercions will fail to compile:
 582   // EXPECT_EQ(0, strict_cast<int>(static_cast<size_t>(0)));
 583   // EXPECT_EQ(0, strict_cast<size_t>(static_cast<int>(0)));
 584   // EXPECT_EQ(1ULL, StrictNumeric<size_t>(1));
 585   // EXPECT_EQ(1, StrictNumeric<size_t>(1U));
 586
 587   // Test various saturation corner cases.
 588   EXPECT_EQ(saturated_cast<int>(small_negative),
 589             static_cast<int>(small_negative));
 590   EXPECT_EQ(saturated_cast<int>(small_positive),
 591             static_cast<int>(small_positive));
 592   EXPECT_EQ(saturated_cast<unsigned>(small_negative),
 593             static_cast<unsigned>(0));
 594   EXPECT_EQ(saturated_cast<int>(double_small),
 595             static_cast<int>(double_small));
 596   EXPECT_EQ(saturated_cast<int>(double_large), numeric_limits<int>::max());
 597   EXPECT_EQ(saturated_cast<float>(double_large), double_infinity);
 598   EXPECT_EQ(saturated_cast<float>(-double_large), -double_infinity);
 599   EXPECT_EQ(numeric_limits<int>::min(), saturated_cast<int>(double_small_int));
 600   EXPECT_EQ(numeric_limits<int>::max(), saturated_cast<int>(double_large_int));
 601 }
 602