From 36d22d82aa202bb199967e9512281e9a53db42c9 Mon Sep 17 00:00:00 2001
From: Daniel Baumann <daniel.baumann@progress-linux.org>
Date: Sun, 7 Apr 2024 21:33:14 +0200
Subject: Adding upstream version 115.7.0esr.

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
---
 .../base/anglebase/numerics/checked_math.h         | 384 +++++++++++++++++++++
 1 file changed, 384 insertions(+)
 create mode 100644 gfx/angle/checkout/src/common/third_party/base/anglebase/numerics/checked_math.h

(limited to 'gfx/angle/checkout/src/common/third_party/base/anglebase/numerics/checked_math.h')

diff --git a/gfx/angle/checkout/src/common/third_party/base/anglebase/numerics/checked_math.h b/gfx/angle/checkout/src/common/third_party/base/anglebase/numerics/checked_math.h
new file mode 100644
index 0000000000..18bceb7468
--- /dev/null
+++ b/gfx/angle/checkout/src/common/third_party/base/anglebase/numerics/checked_math.h
@@ -0,0 +1,384 @@
+// Copyright 2017 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.
+
+#ifndef BASE_NUMERICS_CHECKED_MATH_H_
+#define BASE_NUMERICS_CHECKED_MATH_H_
+
+#include <stddef.h>
+
+#include <limits>
+#include <type_traits>
+
+#include "anglebase/numerics/checked_math_impl.h"
+
+namespace angle
+{
+namespace base
+{
+namespace internal
+{
+
+template <typename T>
+class CheckedNumeric
+{
+    static_assert(std::is_arithmetic<T>::value, "CheckedNumeric<T>: T must be a numeric type.");
+
+  public:
+    template <typename Src>
+    friend class CheckedNumeric;
+
+    using type = T;
+
+    constexpr CheckedNumeric() = default;
+
+    // Copy constructor.
+    template <typename Src>
+    constexpr CheckedNumeric(const CheckedNumeric<Src> &rhs)
+        : state_(rhs.state_.value(), rhs.IsValid())
+    {}
+
+    // This is not an explicit constructor because we implicitly upgrade regular
+    // numerics to CheckedNumerics to make them easier to use.
+    template <typename Src>
+    constexpr CheckedNumeric(Src value)  // NOLINT(runtime/explicit)
+        : state_(value)
+    {
+        static_assert(std::is_arithmetic<Src>::value, "Argument must be numeric.");
+    }
+
+    // This is not an explicit constructor because we want a seamless conversion
+    // from StrictNumeric types.
+    template <typename Src>
+    constexpr CheckedNumeric(StrictNumeric<Src> value)  // NOLINT(runtime/explicit)
+        : state_(static_cast<Src>(value))
+    {}
+
+    // IsValid() - The public API to test if a CheckedNumeric is currently valid.
+    // A range checked destination type can be supplied using the Dst template
+    // parameter.
+    template <typename Dst = T>
+    constexpr bool IsValid() const
+    {
+        return state_.is_valid() && IsValueInRangeForNumericType<Dst>(state_.value());
+    }
+
+    // AssignIfValid(Dst) - Assigns the underlying value if it is currently valid
+    // and is within the range supported by the destination type. Returns true if
+    // successful and false otherwise.
+    template <typename Dst>
+#if defined(__clang__) || defined(__GNUC__)
+    __attribute__((warn_unused_result))
+#elif defined(_MSC_VER)
+    _Check_return_
+#endif
+    constexpr bool
+    AssignIfValid(Dst *result) const
+    {
+        return BASE_NUMERICS_LIKELY(IsValid<Dst>())
+                   ? ((*result = static_cast<Dst>(state_.value())), true)
+                   : false;
+    }
+
+    // ValueOrDie() - The primary accessor for the underlying value. If the
+    // current state is not valid it will CHECK and crash.
+    // A range checked destination type can be supplied using the Dst template
+    // parameter, which will trigger a CHECK if the value is not in bounds for
+    // the destination.
+    // The CHECK behavior can be overridden by supplying a handler as a
+    // template parameter, for test code, etc. However, the handler cannot access
+    // the underlying value, and it is not available through other means.
+    template <typename Dst = T, class CheckHandler = CheckOnFailure>
+    constexpr StrictNumeric<Dst> ValueOrDie() const
+    {
+        return BASE_NUMERICS_LIKELY(IsValid<Dst>()) ? static_cast<Dst>(state_.value())
+                                                    : CheckHandler::template HandleFailure<Dst>();
+    }
+
+    // ValueOrDefault(T default_value) - A convenience method that returns the
+    // current value if the state is valid, and the supplied default_value for
+    // any other state.
+    // A range checked destination type can be supplied using the Dst template
+    // parameter. WARNING: This function may fail to compile or CHECK at runtime
+    // if the supplied default_value is not within range of the destination type.
+    template <typename Dst = T, typename Src>
+    constexpr StrictNumeric<Dst> ValueOrDefault(const Src default_value) const
+    {
+        return BASE_NUMERICS_LIKELY(IsValid<Dst>()) ? static_cast<Dst>(state_.value())
+                                                    : checked_cast<Dst>(default_value);
+    }
+
+    // Returns a checked numeric of the specified type, cast from the current
+    // CheckedNumeric. If the current state is invalid or the destination cannot
+    // represent the result then the returned CheckedNumeric will be invalid.
+    template <typename Dst>
+    constexpr CheckedNumeric<typename UnderlyingType<Dst>::type> Cast() const
+    {
+        return *this;
+    }
+
+    // This friend method is available solely for providing more detailed logging
+    // in the tests. Do not implement it in production code, because the
+    // underlying values may change at any time.
+    template <typename U>
+    friend U GetNumericValueForTest(const CheckedNumeric<U> &src);
+
+    // Prototypes for the supported arithmetic operator overloads.
+    template <typename Src>
+    constexpr CheckedNumeric &operator+=(const Src rhs);
+    template <typename Src>
+    constexpr CheckedNumeric &operator-=(const Src rhs);
+    template <typename Src>
+    constexpr CheckedNumeric &operator*=(const Src rhs);
+    template <typename Src>
+    constexpr CheckedNumeric &operator/=(const Src rhs);
+    template <typename Src>
+    constexpr CheckedNumeric &operator%=(const Src rhs);
+    template <typename Src>
+    constexpr CheckedNumeric &operator<<=(const Src rhs);
+    template <typename Src>
+    constexpr CheckedNumeric &operator>>=(const Src rhs);
+    template <typename Src>
+    constexpr CheckedNumeric &operator&=(const Src rhs);
+    template <typename Src>
+    constexpr CheckedNumeric &operator|=(const Src rhs);
+    template <typename Src>
+    constexpr CheckedNumeric &operator^=(const Src rhs);
+
+    constexpr CheckedNumeric operator-() const
+    {
+        // Use an optimized code path for a known run-time variable.
+        if (!MustTreatAsConstexpr(state_.value()) && std::is_signed<T>::value &&
+            std::is_floating_point<T>::value)
+        {
+            return FastRuntimeNegate();
+        }
+        // The negation of two's complement int min is int min.
+        const bool is_valid =
+            IsValid() && (!std::is_signed<T>::value || std::is_floating_point<T>::value ||
+                          NegateWrapper(state_.value()) != std::numeric_limits<T>::lowest());
+        return CheckedNumeric<T>(NegateWrapper(state_.value()), is_valid);
+    }
+
+    constexpr CheckedNumeric operator~() const
+    {
+        return CheckedNumeric<decltype(InvertWrapper(T()))>(InvertWrapper(state_.value()),
+                                                            IsValid());
+    }
+
+    constexpr CheckedNumeric Abs() const
+    {
+        return !IsValueNegative(state_.value()) ? *this : -*this;
+    }
+
+    template <typename U>
+    constexpr CheckedNumeric<typename MathWrapper<CheckedMaxOp, T, U>::type> Max(const U rhs) const
+    {
+        return CheckMax(*this, rhs);
+    }
+
+    template <typename U>
+    constexpr CheckedNumeric<typename MathWrapper<CheckedMinOp, T, U>::type> Min(const U rhs) const
+    {
+        return CheckMin(*this, rhs);
+    }
+
+    // This function is available only for integral types. It returns an unsigned
+    // integer of the same width as the source type, containing the absolute value
+    // of the source, and properly handling signed min.
+    constexpr CheckedNumeric<typename UnsignedOrFloatForSize<T>::type> UnsignedAbs() const
+    {
+        return CheckedNumeric<typename UnsignedOrFloatForSize<T>::type>(
+            SafeUnsignedAbs(state_.value()), state_.is_valid());
+    }
+
+    constexpr CheckedNumeric &operator++()
+    {
+        *this += 1;
+        return *this;
+    }
+
+    constexpr CheckedNumeric operator++(int)
+    {
+        CheckedNumeric value = *this;
+        *this += 1;
+        return value;
+    }
+
+    constexpr CheckedNumeric &operator--()
+    {
+        *this -= 1;
+        return *this;
+    }
+
+    constexpr CheckedNumeric operator--(int)
+    {
+        // TODO(pkasting): Consider std::exchange() once it's constexpr in C++20.
+        const CheckedNumeric value = *this;
+        *this -= 1;
+        return value;
+    }
+
+    // These perform the actual math operations on the CheckedNumerics.
+    // Binary arithmetic operations.
+    template <template <typename, typename, typename> class M, typename L, typename R>
+    static constexpr CheckedNumeric MathOp(const L lhs, const R rhs)
+    {
+        using Math          = typename MathWrapper<M, L, R>::math;
+        T result            = 0;
+        const bool is_valid = Wrapper<L>::is_valid(lhs) && Wrapper<R>::is_valid(rhs) &&
+                              Math::Do(Wrapper<L>::value(lhs), Wrapper<R>::value(rhs), &result);
+        return CheckedNumeric<T>(result, is_valid);
+    }
+
+    // Assignment arithmetic operations.
+    template <template <typename, typename, typename> class M, typename R>
+    constexpr CheckedNumeric &MathOp(const R rhs)
+    {
+        using Math          = typename MathWrapper<M, T, R>::math;
+        T result            = 0;  // Using T as the destination saves a range check.
+        const bool is_valid = state_.is_valid() && Wrapper<R>::is_valid(rhs) &&
+                              Math::Do(state_.value(), Wrapper<R>::value(rhs), &result);
+        *this = CheckedNumeric<T>(result, is_valid);
+        return *this;
+    }
+
+  private:
+    CheckedNumericState<T> state_;
+
+    CheckedNumeric FastRuntimeNegate() const
+    {
+        T result;
+        const bool success = CheckedSubOp<T, T>::Do(T(0), state_.value(), &result);
+        return CheckedNumeric<T>(result, IsValid() && success);
+    }
+
+    template <typename Src>
+    constexpr CheckedNumeric(Src value, bool is_valid) : state_(value, is_valid)
+    {}
+
+    // These wrappers allow us to handle state the same way for both
+    // CheckedNumeric and POD arithmetic types.
+    template <typename Src>
+    struct Wrapper
+    {
+        static constexpr bool is_valid(Src) { return true; }
+        static constexpr Src value(Src value) { return value; }
+    };
+
+    template <typename Src>
+    struct Wrapper<CheckedNumeric<Src>>
+    {
+        static constexpr bool is_valid(const CheckedNumeric<Src> v) { return v.IsValid(); }
+        static constexpr Src value(const CheckedNumeric<Src> v) { return v.state_.value(); }
+    };
+
+    template <typename Src>
+    struct Wrapper<StrictNumeric<Src>>
+    {
+        static constexpr bool is_valid(const StrictNumeric<Src>) { return true; }
+        static constexpr Src value(const StrictNumeric<Src> v) { return static_cast<Src>(v); }
+    };
+};
+
+// Convenience functions to avoid the ugly template disambiguator syntax.
+template <typename Dst, typename Src>
+constexpr bool IsValidForType(const CheckedNumeric<Src> value)
+{
+    return value.template IsValid<Dst>();
+}
+
+template <typename Dst, typename Src>
+constexpr StrictNumeric<Dst> ValueOrDieForType(const CheckedNumeric<Src> value)
+{
+    return value.template ValueOrDie<Dst>();
+}
+
+template <typename Dst, typename Src, typename Default>
+constexpr StrictNumeric<Dst> ValueOrDefaultForType(const CheckedNumeric<Src> value,
+                                                   const Default default_value)
+{
+    return value.template ValueOrDefault<Dst>(default_value);
+}
+
+// Convience wrapper to return a new CheckedNumeric from the provided arithmetic
+// or CheckedNumericType.
+template <typename T>
+constexpr CheckedNumeric<typename UnderlyingType<T>::type> MakeCheckedNum(const T value)
+{
+    return value;
+}
+
+// These implement the variadic wrapper for the math operations.
+template <template <typename, typename, typename> class M, typename L, typename R>
+constexpr CheckedNumeric<typename MathWrapper<M, L, R>::type> CheckMathOp(const L lhs, const R rhs)
+{
+    using Math = typename MathWrapper<M, L, R>::math;
+    return CheckedNumeric<typename Math::result_type>::template MathOp<M>(lhs, rhs);
+}
+
+// General purpose wrapper template for arithmetic operations.
+template <template <typename, typename, typename> class M, typename L, typename R, typename... Args>
+constexpr auto CheckMathOp(const L lhs, const R rhs, const Args... args)
+{
+    return CheckMathOp<M>(CheckMathOp<M>(lhs, rhs), args...);
+}
+
+BASE_NUMERIC_ARITHMETIC_OPERATORS(Checked, Check, Add, +, +=)
+BASE_NUMERIC_ARITHMETIC_OPERATORS(Checked, Check, Sub, -, -=)
+BASE_NUMERIC_ARITHMETIC_OPERATORS(Checked, Check, Mul, *, *=)
+BASE_NUMERIC_ARITHMETIC_OPERATORS(Checked, Check, Div, /, /=)
+BASE_NUMERIC_ARITHMETIC_OPERATORS(Checked, Check, Mod, %, %=)
+BASE_NUMERIC_ARITHMETIC_OPERATORS(Checked, Check, Lsh, <<, <<=)
+BASE_NUMERIC_ARITHMETIC_OPERATORS(Checked, Check, Rsh, >>, >>=)
+BASE_NUMERIC_ARITHMETIC_OPERATORS(Checked, Check, And, &, &=)
+BASE_NUMERIC_ARITHMETIC_OPERATORS(Checked, Check, Or, |, |=)
+BASE_NUMERIC_ARITHMETIC_OPERATORS(Checked, Check, Xor, ^, ^=)
+BASE_NUMERIC_ARITHMETIC_VARIADIC(Checked, Check, Max)
+BASE_NUMERIC_ARITHMETIC_VARIADIC(Checked, Check, Min)
+
+// These are some extra StrictNumeric operators to support simple pointer
+// arithmetic with our result types. Since wrapping on a pointer is always
+// bad, we trigger the CHECK condition here.
+template <typename L, typename R>
+L *operator+(L *lhs, const StrictNumeric<R> rhs)
+{
+    const uintptr_t result =
+        CheckAdd(reinterpret_cast<uintptr_t>(lhs), CheckMul(sizeof(L), static_cast<R>(rhs)))
+            .template ValueOrDie<uintptr_t>();
+    return reinterpret_cast<L *>(result);
+}
+
+template <typename L, typename R>
+L *operator-(L *lhs, const StrictNumeric<R> rhs)
+{
+    const uintptr_t result =
+        CheckSub(reinterpret_cast<uintptr_t>(lhs), CheckMul(sizeof(L), static_cast<R>(rhs)))
+            .template ValueOrDie<uintptr_t>();
+    return reinterpret_cast<L *>(result);
+}
+
+}  // namespace internal
+
+using internal::CheckAdd;
+using internal::CheckAnd;
+using internal::CheckDiv;
+using internal::CheckedNumeric;
+using internal::CheckLsh;
+using internal::CheckMax;
+using internal::CheckMin;
+using internal::CheckMod;
+using internal::CheckMul;
+using internal::CheckOr;
+using internal::CheckRsh;
+using internal::CheckSub;
+using internal::CheckXor;
+using internal::IsValidForType;
+using internal::MakeCheckedNum;
+using internal::ValueOrDefaultForType;
+using internal::ValueOrDieForType;
+
+}  // namespace base
+}  // namespace angle
+
+#endif  // BASE_NUMERICS_CHECKED_MATH_H_
-- 
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