Upgrade to 3.29
Update V8 to 3.29.88.17 and update makefiles to support building on
all the relevant platforms.
Bug: 17370214
Change-Id: Ia3407c157fd8d72a93e23d8318ccaf6ecf77fa4e
diff --git a/src/base/safe_math_impl.h b/src/base/safe_math_impl.h
new file mode 100644
index 0000000..055e2a0
--- /dev/null
+++ b/src/base/safe_math_impl.h
@@ -0,0 +1,531 @@
+// Copyright 2014 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.
+
+// Slightly adapted for inclusion in V8.
+// Copyright 2014 the V8 project authors. All rights reserved.
+
+#ifndef V8_BASE_SAFE_MATH_IMPL_H_
+#define V8_BASE_SAFE_MATH_IMPL_H_
+
+#include <stdint.h>
+
+#include <cmath>
+#include <cstdlib>
+#include <limits>
+
+#include "src/base/macros.h"
+#include "src/base/safe_conversions.h"
+
+namespace v8 {
+namespace base {
+namespace internal {
+
+
+// From Chromium's base/template_util.h:
+
+template<class T, T v>
+struct integral_constant {
+ static const T value = v;
+ typedef T value_type;
+ typedef integral_constant<T, v> type;
+};
+
+template <class T, T v> const T integral_constant<T, v>::value;
+
+typedef integral_constant<bool, true> true_type;
+typedef integral_constant<bool, false> false_type;
+
+template <class T, class U> struct is_same : public false_type {};
+template <class T> struct is_same<T, T> : true_type {};
+
+template<bool B, class T = void>
+struct enable_if {};
+
+template<class T>
+struct enable_if<true, T> { typedef T type; };
+
+// </template_util.h>
+
+
+// Everything from here up to the floating point operations is portable C++,
+// but it may not be fast. This code could be split based on
+// platform/architecture and replaced with potentially faster implementations.
+
+// Integer promotion templates used by the portable checked integer arithmetic.
+template <size_t Size, bool IsSigned>
+struct IntegerForSizeAndSign;
+template <>
+struct IntegerForSizeAndSign<1, true> {
+ typedef int8_t type;
+};
+template <>
+struct IntegerForSizeAndSign<1, false> {
+ typedef uint8_t type;
+};
+template <>
+struct IntegerForSizeAndSign<2, true> {
+ typedef int16_t type;
+};
+template <>
+struct IntegerForSizeAndSign<2, false> {
+ typedef uint16_t type;
+};
+template <>
+struct IntegerForSizeAndSign<4, true> {
+ typedef int32_t type;
+};
+template <>
+struct IntegerForSizeAndSign<4, false> {
+ typedef uint32_t type;
+};
+template <>
+struct IntegerForSizeAndSign<8, true> {
+ typedef int64_t type;
+};
+template <>
+struct IntegerForSizeAndSign<8, false> {
+ typedef uint64_t type;
+};
+
+// WARNING: We have no IntegerForSizeAndSign<16, *>. If we ever add one to
+// support 128-bit math, then the ArithmeticPromotion template below will need
+// to be updated (or more likely replaced with a decltype expression).
+
+template <typename Integer>
+struct UnsignedIntegerForSize {
+ typedef typename enable_if<
+ std::numeric_limits<Integer>::is_integer,
+ typename IntegerForSizeAndSign<sizeof(Integer), false>::type>::type type;
+};
+
+template <typename Integer>
+struct SignedIntegerForSize {
+ typedef typename enable_if<
+ std::numeric_limits<Integer>::is_integer,
+ typename IntegerForSizeAndSign<sizeof(Integer), true>::type>::type type;
+};
+
+template <typename Integer>
+struct TwiceWiderInteger {
+ typedef typename enable_if<
+ std::numeric_limits<Integer>::is_integer,
+ typename IntegerForSizeAndSign<
+ sizeof(Integer) * 2,
+ std::numeric_limits<Integer>::is_signed>::type>::type type;
+};
+
+template <typename Integer>
+struct PositionOfSignBit {
+ static const typename enable_if<std::numeric_limits<Integer>::is_integer,
+ size_t>::type value = 8 * sizeof(Integer) - 1;
+};
+
+// Helper templates for integer manipulations.
+
+template <typename T>
+bool HasSignBit(T x) {
+ // Cast to unsigned since right shift on signed is undefined.
+ return !!(static_cast<typename UnsignedIntegerForSize<T>::type>(x) >>
+ PositionOfSignBit<T>::value);
+}
+
+// This wrapper undoes the standard integer promotions.
+template <typename T>
+T BinaryComplement(T x) {
+ return ~x;
+}
+
+// Here are the actual portable checked integer math implementations.
+// TODO(jschuh): Break this code out from the enable_if pattern and find a clean
+// way to coalesce things into the CheckedNumericState specializations below.
+
+template <typename T>
+typename enable_if<std::numeric_limits<T>::is_integer, T>::type
+CheckedAdd(T x, T y, RangeConstraint* validity) {
+ // Since the value of x+y is undefined if we have a signed type, we compute
+ // it using the unsigned type of the same size.
+ typedef typename UnsignedIntegerForSize<T>::type UnsignedDst;
+ UnsignedDst ux = static_cast<UnsignedDst>(x);
+ UnsignedDst uy = static_cast<UnsignedDst>(y);
+ UnsignedDst uresult = ux + uy;
+ // Addition is valid if the sign of (x + y) is equal to either that of x or
+ // that of y.
+ if (std::numeric_limits<T>::is_signed) {
+ if (HasSignBit(BinaryComplement((uresult ^ ux) & (uresult ^ uy))))
+ *validity = RANGE_VALID;
+ else // Direction of wrap is inverse of result sign.
+ *validity = HasSignBit(uresult) ? RANGE_OVERFLOW : RANGE_UNDERFLOW;
+
+ } else { // Unsigned is either valid or overflow.
+ *validity = BinaryComplement(x) >= y ? RANGE_VALID : RANGE_OVERFLOW;
+ }
+ return static_cast<T>(uresult);
+}
+
+template <typename T>
+typename enable_if<std::numeric_limits<T>::is_integer, T>::type
+CheckedSub(T x, T y, RangeConstraint* validity) {
+ // Since the value of x+y is undefined if we have a signed type, we compute
+ // it using the unsigned type of the same size.
+ typedef typename UnsignedIntegerForSize<T>::type UnsignedDst;
+ UnsignedDst ux = static_cast<UnsignedDst>(x);
+ UnsignedDst uy = static_cast<UnsignedDst>(y);
+ UnsignedDst uresult = ux - uy;
+ // Subtraction is valid if either x and y have same sign, or (x-y) and x have
+ // the same sign.
+ if (std::numeric_limits<T>::is_signed) {
+ if (HasSignBit(BinaryComplement((uresult ^ ux) & (ux ^ uy))))
+ *validity = RANGE_VALID;
+ else // Direction of wrap is inverse of result sign.
+ *validity = HasSignBit(uresult) ? RANGE_OVERFLOW : RANGE_UNDERFLOW;
+
+ } else { // Unsigned is either valid or underflow.
+ *validity = x >= y ? RANGE_VALID : RANGE_UNDERFLOW;
+ }
+ return static_cast<T>(uresult);
+}
+
+// Integer multiplication is a bit complicated. In the fast case we just
+// we just promote to a twice wider type, and range check the result. In the
+// slow case we need to manually check that the result won't be truncated by
+// checking with division against the appropriate bound.
+template <typename T>
+typename enable_if<
+ std::numeric_limits<T>::is_integer && sizeof(T) * 2 <= sizeof(uintmax_t),
+ T>::type
+CheckedMul(T x, T y, RangeConstraint* validity) {
+ typedef typename TwiceWiderInteger<T>::type IntermediateType;
+ IntermediateType tmp =
+ static_cast<IntermediateType>(x) * static_cast<IntermediateType>(y);
+ *validity = DstRangeRelationToSrcRange<T>(tmp);
+ return static_cast<T>(tmp);
+}
+
+template <typename T>
+typename enable_if<std::numeric_limits<T>::is_integer &&
+ std::numeric_limits<T>::is_signed &&
+ (sizeof(T) * 2 > sizeof(uintmax_t)),
+ T>::type
+CheckedMul(T x, T y, RangeConstraint* validity) {
+ // if either side is zero then the result will be zero.
+ if (!(x || y)) {
+ return RANGE_VALID;
+
+ } else if (x > 0) {
+ if (y > 0)
+ *validity =
+ x <= std::numeric_limits<T>::max() / y ? RANGE_VALID : RANGE_OVERFLOW;
+ else
+ *validity = y >= std::numeric_limits<T>::min() / x ? RANGE_VALID
+ : RANGE_UNDERFLOW;
+
+ } else {
+ if (y > 0)
+ *validity = x >= std::numeric_limits<T>::min() / y ? RANGE_VALID
+ : RANGE_UNDERFLOW;
+ else
+ *validity =
+ y >= std::numeric_limits<T>::max() / x ? RANGE_VALID : RANGE_OVERFLOW;
+ }
+
+ return x * y;
+}
+
+template <typename T>
+typename enable_if<std::numeric_limits<T>::is_integer &&
+ !std::numeric_limits<T>::is_signed &&
+ (sizeof(T) * 2 > sizeof(uintmax_t)),
+ T>::type
+CheckedMul(T x, T y, RangeConstraint* validity) {
+ *validity = (y == 0 || x <= std::numeric_limits<T>::max() / y)
+ ? RANGE_VALID
+ : RANGE_OVERFLOW;
+ return x * y;
+}
+
+// Division just requires a check for an invalid negation on signed min/-1.
+template <typename T>
+T CheckedDiv(
+ T x,
+ T y,
+ RangeConstraint* validity,
+ typename enable_if<std::numeric_limits<T>::is_integer, int>::type = 0) {
+ if (std::numeric_limits<T>::is_signed && x == std::numeric_limits<T>::min() &&
+ y == static_cast<T>(-1)) {
+ *validity = RANGE_OVERFLOW;
+ return std::numeric_limits<T>::min();
+ }
+
+ *validity = RANGE_VALID;
+ return x / y;
+}
+
+template <typename T>
+typename enable_if<
+ std::numeric_limits<T>::is_integer && std::numeric_limits<T>::is_signed,
+ T>::type
+CheckedMod(T x, T y, RangeConstraint* validity) {
+ *validity = y > 0 ? RANGE_VALID : RANGE_INVALID;
+ return x % y;
+}
+
+template <typename T>
+typename enable_if<
+ std::numeric_limits<T>::is_integer && !std::numeric_limits<T>::is_signed,
+ T>::type
+CheckedMod(T x, T y, RangeConstraint* validity) {
+ *validity = RANGE_VALID;
+ return x % y;
+}
+
+template <typename T>
+typename enable_if<
+ std::numeric_limits<T>::is_integer && std::numeric_limits<T>::is_signed,
+ T>::type
+CheckedNeg(T value, RangeConstraint* validity) {
+ *validity =
+ value != std::numeric_limits<T>::min() ? RANGE_VALID : RANGE_OVERFLOW;
+ // The negation of signed min is min, so catch that one.
+ return -value;
+}
+
+template <typename T>
+typename enable_if<
+ std::numeric_limits<T>::is_integer && !std::numeric_limits<T>::is_signed,
+ T>::type
+CheckedNeg(T value, RangeConstraint* validity) {
+ // The only legal unsigned negation is zero.
+ *validity = value ? RANGE_UNDERFLOW : RANGE_VALID;
+ return static_cast<T>(
+ -static_cast<typename SignedIntegerForSize<T>::type>(value));
+}
+
+template <typename T>
+typename enable_if<
+ std::numeric_limits<T>::is_integer && std::numeric_limits<T>::is_signed,
+ T>::type
+CheckedAbs(T value, RangeConstraint* validity) {
+ *validity =
+ value != std::numeric_limits<T>::min() ? RANGE_VALID : RANGE_OVERFLOW;
+ return std::abs(value);
+}
+
+template <typename T>
+typename enable_if<
+ std::numeric_limits<T>::is_integer && !std::numeric_limits<T>::is_signed,
+ T>::type
+CheckedAbs(T value, RangeConstraint* validity) {
+ // Absolute value of a positive is just its identiy.
+ *validity = RANGE_VALID;
+ return value;
+}
+
+// These are the floating point stubs that the compiler needs to see. Only the
+// negation operation is ever called.
+#define BASE_FLOAT_ARITHMETIC_STUBS(NAME) \
+ template <typename T> \
+ typename enable_if<std::numeric_limits<T>::is_iec559, T>::type \
+ Checked##NAME(T, T, RangeConstraint*) { \
+ UNREACHABLE(); \
+ return 0; \
+ }
+
+BASE_FLOAT_ARITHMETIC_STUBS(Add)
+BASE_FLOAT_ARITHMETIC_STUBS(Sub)
+BASE_FLOAT_ARITHMETIC_STUBS(Mul)
+BASE_FLOAT_ARITHMETIC_STUBS(Div)
+BASE_FLOAT_ARITHMETIC_STUBS(Mod)
+
+#undef BASE_FLOAT_ARITHMETIC_STUBS
+
+template <typename T>
+typename enable_if<std::numeric_limits<T>::is_iec559, T>::type CheckedNeg(
+ T value,
+ RangeConstraint*) {
+ return -value;
+}
+
+template <typename T>
+typename enable_if<std::numeric_limits<T>::is_iec559, T>::type CheckedAbs(
+ T value,
+ RangeConstraint*) {
+ return std::abs(value);
+}
+
+// Floats carry around their validity state with them, but integers do not. So,
+// we wrap the underlying value in a specialization in order to hide that detail
+// and expose an interface via accessors.
+enum NumericRepresentation {
+ NUMERIC_INTEGER,
+ NUMERIC_FLOATING,
+ NUMERIC_UNKNOWN
+};
+
+template <typename NumericType>
+struct GetNumericRepresentation {
+ static const NumericRepresentation value =
+ std::numeric_limits<NumericType>::is_integer
+ ? NUMERIC_INTEGER
+ : (std::numeric_limits<NumericType>::is_iec559 ? NUMERIC_FLOATING
+ : NUMERIC_UNKNOWN);
+};
+
+template <typename T, NumericRepresentation type =
+ GetNumericRepresentation<T>::value>
+class CheckedNumericState {};
+
+// Integrals require quite a bit of additional housekeeping to manage state.
+template <typename T>
+class CheckedNumericState<T, NUMERIC_INTEGER> {
+ private:
+ T value_;
+ RangeConstraint validity_;
+
+ public:
+ template <typename Src, NumericRepresentation type>
+ friend class CheckedNumericState;
+
+ CheckedNumericState() : value_(0), validity_(RANGE_VALID) {}
+
+ template <typename Src>
+ CheckedNumericState(Src value, RangeConstraint validity)
+ : value_(value),
+ validity_(GetRangeConstraint(validity |
+ DstRangeRelationToSrcRange<T>(value))) {
+ // Argument must be numeric.
+ STATIC_ASSERT(std::numeric_limits<Src>::is_specialized);
+ }
+
+ // Copy constructor.
+ template <typename Src>
+ CheckedNumericState(const CheckedNumericState<Src>& rhs)
+ : value_(static_cast<T>(rhs.value())),
+ validity_(GetRangeConstraint(
+ rhs.validity() | DstRangeRelationToSrcRange<T>(rhs.value()))) {}
+
+ template <typename Src>
+ explicit CheckedNumericState(
+ Src value,
+ typename enable_if<std::numeric_limits<Src>::is_specialized, int>::type =
+ 0)
+ : value_(static_cast<T>(value)),
+ validity_(DstRangeRelationToSrcRange<T>(value)) {}
+
+ RangeConstraint validity() const { return validity_; }
+ T value() const { return value_; }
+};
+
+// Floating points maintain their own validity, but need translation wrappers.
+template <typename T>
+class CheckedNumericState<T, NUMERIC_FLOATING> {
+ private:
+ T value_;
+
+ public:
+ template <typename Src, NumericRepresentation type>
+ friend class CheckedNumericState;
+
+ CheckedNumericState() : value_(0.0) {}
+
+ template <typename Src>
+ CheckedNumericState(
+ Src value,
+ RangeConstraint validity,
+ typename enable_if<std::numeric_limits<Src>::is_integer, int>::type = 0) {
+ switch (DstRangeRelationToSrcRange<T>(value)) {
+ case RANGE_VALID:
+ value_ = static_cast<T>(value);
+ break;
+
+ case RANGE_UNDERFLOW:
+ value_ = -std::numeric_limits<T>::infinity();
+ break;
+
+ case RANGE_OVERFLOW:
+ value_ = std::numeric_limits<T>::infinity();
+ break;
+
+ case RANGE_INVALID:
+ value_ = std::numeric_limits<T>::quiet_NaN();
+ break;
+ }
+ }
+
+ template <typename Src>
+ explicit CheckedNumericState(
+ Src value,
+ typename enable_if<std::numeric_limits<Src>::is_specialized, int>::type =
+ 0)
+ : value_(static_cast<T>(value)) {}
+
+ // Copy constructor.
+ template <typename Src>
+ CheckedNumericState(const CheckedNumericState<Src>& rhs)
+ : value_(static_cast<T>(rhs.value())) {}
+
+ RangeConstraint validity() const {
+ return GetRangeConstraint(value_ <= std::numeric_limits<T>::max(),
+ value_ >= -std::numeric_limits<T>::max());
+ }
+ T value() const { return value_; }
+};
+
+// For integers less than 128-bit and floats 32-bit or larger, we can distil
+// C/C++ arithmetic promotions down to two simple rules:
+// 1. The type with the larger maximum exponent always takes precedence.
+// 2. The resulting type must be promoted to at least an int.
+// The following template specializations implement that promotion logic.
+enum ArithmeticPromotionCategory {
+ LEFT_PROMOTION,
+ RIGHT_PROMOTION,
+ DEFAULT_PROMOTION
+};
+
+template <typename Lhs,
+ typename Rhs = Lhs,
+ ArithmeticPromotionCategory Promotion =
+ (MaxExponent<Lhs>::value > MaxExponent<Rhs>::value)
+ ? (MaxExponent<Lhs>::value > MaxExponent<int>::value
+ ? LEFT_PROMOTION
+ : DEFAULT_PROMOTION)
+ : (MaxExponent<Rhs>::value > MaxExponent<int>::value
+ ? RIGHT_PROMOTION
+ : DEFAULT_PROMOTION) >
+struct ArithmeticPromotion;
+
+template <typename Lhs, typename Rhs>
+struct ArithmeticPromotion<Lhs, Rhs, LEFT_PROMOTION> {
+ typedef Lhs type;
+};
+
+template <typename Lhs, typename Rhs>
+struct ArithmeticPromotion<Lhs, Rhs, RIGHT_PROMOTION> {
+ typedef Rhs type;
+};
+
+template <typename Lhs, typename Rhs>
+struct ArithmeticPromotion<Lhs, Rhs, DEFAULT_PROMOTION> {
+ typedef int type;
+};
+
+// We can statically check if operations on the provided types can wrap, so we
+// can skip the checked operations if they're not needed. So, for an integer we
+// care if the destination type preserves the sign and is twice the width of
+// the source.
+template <typename T, typename Lhs, typename Rhs>
+struct IsIntegerArithmeticSafe {
+ static const bool value = !std::numeric_limits<T>::is_iec559 &&
+ StaticDstRangeRelationToSrcRange<T, Lhs>::value ==
+ NUMERIC_RANGE_CONTAINED &&
+ sizeof(T) >= (2 * sizeof(Lhs)) &&
+ StaticDstRangeRelationToSrcRange<T, Rhs>::value !=
+ NUMERIC_RANGE_CONTAINED &&
+ sizeof(T) >= (2 * sizeof(Rhs));
+};
+
+} // namespace internal
+} // namespace base
+} // namespace v8
+
+#endif // V8_BASE_SAFE_MATH_IMPL_H_