Update to current webrtc library
This is from the upstream library commit id 3326535126e435f1ba647885ce43a8f0f3d317eb, corresponding to Chromium 88.0.4290.1.
This commit is contained in:
177
webrtc/rtc_base/numerics/safe_conversions_impl.h
Normal file
177
webrtc/rtc_base/numerics/safe_conversions_impl.h
Normal file
@ -0,0 +1,177 @@
|
||||
/*
|
||||
* Copyright 2014 The WebRTC Project Authors. All rights reserved.
|
||||
*
|
||||
* Use of this source code is governed by a BSD-style license
|
||||
* that can be found in the LICENSE file in the root of the source
|
||||
* tree. An additional intellectual property rights grant can be found
|
||||
* in the file PATENTS. All contributing project authors may
|
||||
* be found in the AUTHORS file in the root of the source tree.
|
||||
*/
|
||||
|
||||
// Borrowed from Chromium's src/base/numerics/safe_conversions_impl.h.
|
||||
|
||||
#ifndef RTC_BASE_NUMERICS_SAFE_CONVERSIONS_IMPL_H_
|
||||
#define RTC_BASE_NUMERICS_SAFE_CONVERSIONS_IMPL_H_
|
||||
|
||||
#include <limits>
|
||||
|
||||
namespace rtc {
|
||||
namespace internal {
|
||||
|
||||
enum DstSign { DST_UNSIGNED, DST_SIGNED };
|
||||
|
||||
enum SrcSign { SRC_UNSIGNED, SRC_SIGNED };
|
||||
|
||||
enum DstRange { OVERLAPS_RANGE, CONTAINS_RANGE };
|
||||
|
||||
// Helper templates to statically determine if our destination type can contain
|
||||
// all values represented by the source type.
|
||||
|
||||
template <typename Dst,
|
||||
typename Src,
|
||||
DstSign IsDstSigned =
|
||||
std::numeric_limits<Dst>::is_signed ? DST_SIGNED : DST_UNSIGNED,
|
||||
SrcSign IsSrcSigned =
|
||||
std::numeric_limits<Src>::is_signed ? SRC_SIGNED : SRC_UNSIGNED>
|
||||
struct StaticRangeCheck {};
|
||||
|
||||
template <typename Dst, typename Src>
|
||||
struct StaticRangeCheck<Dst, Src, DST_SIGNED, SRC_SIGNED> {
|
||||
typedef std::numeric_limits<Dst> DstLimits;
|
||||
typedef std::numeric_limits<Src> SrcLimits;
|
||||
// Compare based on max_exponent, which we must compute for integrals.
|
||||
static const size_t kDstMaxExponent =
|
||||
DstLimits::is_iec559 ? DstLimits::max_exponent : (sizeof(Dst) * 8 - 1);
|
||||
static const size_t kSrcMaxExponent =
|
||||
SrcLimits::is_iec559 ? SrcLimits::max_exponent : (sizeof(Src) * 8 - 1);
|
||||
static const DstRange value =
|
||||
kDstMaxExponent >= kSrcMaxExponent ? CONTAINS_RANGE : OVERLAPS_RANGE;
|
||||
};
|
||||
|
||||
template <typename Dst, typename Src>
|
||||
struct StaticRangeCheck<Dst, Src, DST_UNSIGNED, SRC_UNSIGNED> {
|
||||
static const DstRange value =
|
||||
sizeof(Dst) >= sizeof(Src) ? CONTAINS_RANGE : OVERLAPS_RANGE;
|
||||
};
|
||||
|
||||
template <typename Dst, typename Src>
|
||||
struct StaticRangeCheck<Dst, Src, DST_SIGNED, SRC_UNSIGNED> {
|
||||
typedef std::numeric_limits<Dst> DstLimits;
|
||||
typedef std::numeric_limits<Src> SrcLimits;
|
||||
// Compare based on max_exponent, which we must compute for integrals.
|
||||
static const size_t kDstMaxExponent =
|
||||
DstLimits::is_iec559 ? DstLimits::max_exponent : (sizeof(Dst) * 8 - 1);
|
||||
static const size_t kSrcMaxExponent = sizeof(Src) * 8;
|
||||
static const DstRange value =
|
||||
kDstMaxExponent >= kSrcMaxExponent ? CONTAINS_RANGE : OVERLAPS_RANGE;
|
||||
};
|
||||
|
||||
template <typename Dst, typename Src>
|
||||
struct StaticRangeCheck<Dst, Src, DST_UNSIGNED, SRC_SIGNED> {
|
||||
static const DstRange value = OVERLAPS_RANGE;
|
||||
};
|
||||
|
||||
enum RangeCheckResult {
|
||||
TYPE_VALID = 0, // Value can be represented by the destination type.
|
||||
TYPE_UNDERFLOW = 1, // Value would overflow.
|
||||
TYPE_OVERFLOW = 2, // Value would underflow.
|
||||
TYPE_INVALID = 3 // Source value is invalid (i.e. NaN).
|
||||
};
|
||||
|
||||
// This macro creates a RangeCheckResult from an upper and lower bound
|
||||
// check by taking advantage of the fact that only NaN can be out of range in
|
||||
// both directions at once.
|
||||
#define BASE_NUMERIC_RANGE_CHECK_RESULT(is_in_upper_bound, is_in_lower_bound) \
|
||||
RangeCheckResult(((is_in_upper_bound) ? 0 : TYPE_OVERFLOW) | \
|
||||
((is_in_lower_bound) ? 0 : TYPE_UNDERFLOW))
|
||||
|
||||
template <typename Dst,
|
||||
typename Src,
|
||||
DstSign IsDstSigned =
|
||||
std::numeric_limits<Dst>::is_signed ? DST_SIGNED : DST_UNSIGNED,
|
||||
SrcSign IsSrcSigned =
|
||||
std::numeric_limits<Src>::is_signed ? SRC_SIGNED : SRC_UNSIGNED,
|
||||
DstRange IsSrcRangeContained = StaticRangeCheck<Dst, Src>::value>
|
||||
struct RangeCheckImpl {};
|
||||
|
||||
// The following templates are for ranges that must be verified at runtime. We
|
||||
// split it into checks based on signedness to avoid confusing casts and
|
||||
// compiler warnings on signed an unsigned comparisons.
|
||||
|
||||
// Dst range always contains the result: nothing to check.
|
||||
template <typename Dst, typename Src, DstSign IsDstSigned, SrcSign IsSrcSigned>
|
||||
struct RangeCheckImpl<Dst, Src, IsDstSigned, IsSrcSigned, CONTAINS_RANGE> {
|
||||
static constexpr RangeCheckResult Check(Src value) { return TYPE_VALID; }
|
||||
};
|
||||
|
||||
// Signed to signed narrowing.
|
||||
template <typename Dst, typename Src>
|
||||
struct RangeCheckImpl<Dst, Src, DST_SIGNED, SRC_SIGNED, OVERLAPS_RANGE> {
|
||||
static constexpr RangeCheckResult Check(Src value) {
|
||||
typedef std::numeric_limits<Dst> DstLimits;
|
||||
return DstLimits::is_iec559
|
||||
? BASE_NUMERIC_RANGE_CHECK_RESULT(
|
||||
value <= static_cast<Src>(DstLimits::max()),
|
||||
value >= static_cast<Src>(DstLimits::max() * -1))
|
||||
: BASE_NUMERIC_RANGE_CHECK_RESULT(
|
||||
value <= static_cast<Src>(DstLimits::max()),
|
||||
value >= static_cast<Src>(DstLimits::min()));
|
||||
}
|
||||
};
|
||||
|
||||
// Unsigned to unsigned narrowing.
|
||||
template <typename Dst, typename Src>
|
||||
struct RangeCheckImpl<Dst, Src, DST_UNSIGNED, SRC_UNSIGNED, OVERLAPS_RANGE> {
|
||||
static constexpr RangeCheckResult Check(Src value) {
|
||||
typedef std::numeric_limits<Dst> DstLimits;
|
||||
return BASE_NUMERIC_RANGE_CHECK_RESULT(
|
||||
value <= static_cast<Src>(DstLimits::max()), true);
|
||||
}
|
||||
};
|
||||
|
||||
// Unsigned to signed.
|
||||
template <typename Dst, typename Src>
|
||||
struct RangeCheckImpl<Dst, Src, DST_SIGNED, SRC_UNSIGNED, OVERLAPS_RANGE> {
|
||||
static constexpr RangeCheckResult Check(Src value) {
|
||||
typedef std::numeric_limits<Dst> DstLimits;
|
||||
return sizeof(Dst) > sizeof(Src)
|
||||
? TYPE_VALID
|
||||
: BASE_NUMERIC_RANGE_CHECK_RESULT(
|
||||
value <= static_cast<Src>(DstLimits::max()), true);
|
||||
}
|
||||
};
|
||||
|
||||
// Signed to unsigned.
|
||||
template <typename Dst, typename Src>
|
||||
struct RangeCheckImpl<Dst, Src, DST_UNSIGNED, SRC_SIGNED, OVERLAPS_RANGE> {
|
||||
typedef std::numeric_limits<Dst> DstLimits;
|
||||
typedef std::numeric_limits<Src> SrcLimits;
|
||||
// Compare based on max_exponent, which we must compute for integrals.
|
||||
static constexpr size_t DstMaxExponent() { return sizeof(Dst) * 8; }
|
||||
static constexpr size_t SrcMaxExponent() {
|
||||
return SrcLimits::is_iec559 ? SrcLimits::max_exponent
|
||||
: (sizeof(Src) * 8 - 1);
|
||||
}
|
||||
static constexpr RangeCheckResult Check(Src value) {
|
||||
return (DstMaxExponent() >= SrcMaxExponent())
|
||||
? BASE_NUMERIC_RANGE_CHECK_RESULT(true,
|
||||
value >= static_cast<Src>(0))
|
||||
: BASE_NUMERIC_RANGE_CHECK_RESULT(
|
||||
value <= static_cast<Src>(DstLimits::max()),
|
||||
value >= static_cast<Src>(0));
|
||||
}
|
||||
};
|
||||
|
||||
template <typename Dst, typename Src>
|
||||
inline constexpr RangeCheckResult RangeCheck(Src value) {
|
||||
static_assert(std::numeric_limits<Src>::is_specialized,
|
||||
"argument must be numeric");
|
||||
static_assert(std::numeric_limits<Dst>::is_specialized,
|
||||
"result must be numeric");
|
||||
return RangeCheckImpl<Dst, Src>::Check(value);
|
||||
}
|
||||
|
||||
} // namespace internal
|
||||
} // namespace rtc
|
||||
|
||||
#endif // RTC_BASE_NUMERICS_SAFE_CONVERSIONS_IMPL_H_
|
Reference in New Issue
Block a user