Index: base/rand_util.cc |
diff --git a/base/rand_util.cc b/base/rand_util.cc |
index 931eb4e943e646e2f39e2848b33683247b5b4725..e12088e54344a9f0ba2de21d45a0cd467bd016df 100644 |
--- a/base/rand_util.cc |
+++ b/base/rand_util.cc |
@@ -10,7 +10,6 @@ |
#include <algorithm> |
#include <limits> |
-#include "base/basictypes.h" |
#include "base/logging.h" |
#include "base/strings/string_util.h" |
@@ -19,8 +18,11 @@ namespace base { |
int RandInt(int min, int max) { |
DCHECK_LE(min, max); |
- uint64 range = static_cast<uint64>(max) - min + 1; |
- int result = min + static_cast<int>(base::RandGenerator(range)); |
+ uint64_t range = static_cast<uint64_t>(max) - min + 1; |
+ // |range| is at most UINT_MAX + 1, so the result of RandGenerator(range) |
+ // is at most UINT_MAX. Hence it's safe to cast it from uint64_t to int64_t. |
+ int result = |
+ static_cast<int>(min + static_cast<int64_t>(base::RandGenerator(range))); |
DCHECK_GE(result, min); |
DCHECK_LE(result, max); |
return result; |
@@ -30,7 +32,7 @@ double RandDouble() { |
return BitsToOpenEndedUnitInterval(base::RandUint64()); |
} |
-double BitsToOpenEndedUnitInterval(uint64 bits) { |
+double BitsToOpenEndedUnitInterval(uint64_t bits) { |
// We try to get maximum precision by masking out as many bits as will fit |
// in the target type's mantissa, and raising it to an appropriate power to |
// produce output in the range [0, 1). For IEEE 754 doubles, the mantissa |
@@ -38,23 +40,23 @@ double BitsToOpenEndedUnitInterval(uint64 bits) { |
COMPILE_ASSERT(std::numeric_limits<double>::radix == 2, otherwise_use_scalbn); |
static const int kBits = std::numeric_limits<double>::digits; |
- uint64 random_bits = bits & ((UINT64_C(1) << kBits) - 1); |
+ uint64_t random_bits = bits & ((UINT64_C(1) << kBits) - 1); |
double result = ldexp(static_cast<double>(random_bits), -1 * kBits); |
DCHECK_GE(result, 0.0); |
DCHECK_LT(result, 1.0); |
return result; |
} |
-uint64 RandGenerator(uint64 range) { |
+uint64_t RandGenerator(uint64_t range) { |
DCHECK_GT(range, 0u); |
// We must discard random results above this number, as they would |
// make the random generator non-uniform (consider e.g. if |
// MAX_UINT64 was 7 and |range| was 5, then a result of 1 would be twice |
// as likely as a result of 3 or 4). |
- uint64 max_acceptable_value = |
- (std::numeric_limits<uint64>::max() / range) * range - 1; |
+ uint64_t max_acceptable_value = |
+ (std::numeric_limits<uint64_t>::max() / range) * range - 1; |
- uint64 value; |
+ uint64_t value; |
do { |
value = base::RandUint64(); |
} while (value > max_acceptable_value); |