Coverage Report

Created: 2026-06-01 18:35

next uncovered line (L), next uncovered region (R), next uncovered branch (B)
/bitcoin/src/util/overflow.h
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// Copyright (c) 2021-present The Bitcoin Core developers
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// Distributed under the MIT software license, see the accompanying
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// file COPYING or http://www.opensource.org/licenses/mit-license.php.
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#ifndef BITCOIN_UTIL_OVERFLOW_H
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#define BITCOIN_UTIL_OVERFLOW_H
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#include <util/check.h>
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#include <climits>
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#include <concepts>
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#include <limits>
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#include <optional>
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#include <type_traits>
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template <std::integral T>
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[[nodiscard]] bool AdditionOverflow(const T i, const T j) noexcept
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{
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    if constexpr (std::numeric_limits<T>::is_signed) {
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        return (i > 0 && j > std::numeric_limits<T>::max() - i) ||
  Branch (20:17): [True: 0, False: 0]
  Branch (20:26): [True: 0, False: 0]

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               (i < 0 && j < std::numeric_limits<T>::min() - i);
  Branch (21:17): [True: 0, False: 0]
  Branch (21:26): [True: 0, False: 0]

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    }
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    return std::numeric_limits<T>::max() - i < j;
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}
Unexecuted instantiation: _Z16AdditionOverflowITkSt8integralmEbT_S0_
Unexecuted instantiation: _Z16AdditionOverflowITkSt8integrallEbT_S0_
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template <class T>
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[[nodiscard]] std::optional<T> CheckedAdd(const T i, const T j) noexcept
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{
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    if (AdditionOverflow(i, j)) {
  Branch (29:9): [True: 0, False: 0]

  Branch (29:9): [True: 0, False: 0]

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        return std::nullopt;
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    }
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    return i + j;
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}
Unexecuted instantiation: std::optional<unsigned long> CheckedAdd<unsigned long>(unsigned long, unsigned long)
Unexecuted instantiation: std::optional<long> CheckedAdd<long>(long, long)
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template <std::unsigned_integral T, std::unsigned_integral U>
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[[nodiscard]] constexpr bool TrySub(T& i, const U j) noexcept
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{
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    if (i < T{j}) return false;
  Branch (38:9): [True: 0, False: 0]

  Branch (38:9): [True: 0, False: 0]

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    i -= T{j};
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    return true;
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}
Unexecuted instantiation: _Z6TrySubITkSt17unsigned_integralmTkSt17unsigned_integralbEbRT_T0_
Unexecuted instantiation: _Z6TrySubITkSt17unsigned_integralmTkSt17unsigned_integralmEbRT_T0_
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template <std::integral T>
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[[nodiscard]] T SaturatingAdd(const T i, const T j) noexcept
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{
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    if constexpr (std::numeric_limits<T>::is_signed) {
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        if (i > 0 && j > std::numeric_limits<T>::max() - i) {
  Branch (47:13): [True: 0, False: 0]
  Branch (47:22): [True: 0, False: 0]

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            return std::numeric_limits<T>::max();
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        }
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        if (i < 0 && j < std::numeric_limits<T>::min() - i) {
  Branch (50:13): [True: 0, False: 0]
  Branch (50:22): [True: 0, False: 0]

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            return std::numeric_limits<T>::min();
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        }
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    } else {
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        if (std::numeric_limits<T>::max() - i < j) {
  Branch (54:13): [True: 0, False: 0]

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            return std::numeric_limits<T>::max();
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        }
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    }
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    return i + j;
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}
Unexecuted instantiation: _Z13SaturatingAddITkSt8integrallET_S0_S0_
Unexecuted instantiation: _Z13SaturatingAddITkSt8integralmET_S0_S0_
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/**
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 * @brief Integer ceiling division (for unsigned values).
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 *
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 * Computes the smallest integer q such that q * divisor >= dividend.
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 * Both dividend and divisor must be unsigned, and divisor must be non-zero.
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 *
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 * The implementation avoids overflow that can occur with `(dividend + divisor - 1) / divisor`.
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 */
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template <std::unsigned_integral Dividend, std::unsigned_integral Divisor>
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[[nodiscard]] constexpr auto CeilDiv(const Dividend dividend, const Divisor divisor)
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{
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    assert(divisor > 0);
  Branch (72:5): [True: 0, False: 0]

  Branch (72:5): [True: 0, False: 0]
  Branch (72:5): [True: 610, False: 0]

  Branch (72:5): [True: 0, False: 0]

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    return dividend / divisor + (dividend % divisor != 0);
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}
Unexecuted instantiation: _Z7CeilDivITkSt17unsigned_integralmTkSt17unsigned_integraljEDaT_T0_
Unexecuted instantiation: _Z7CeilDivITkSt17unsigned_integraljTkSt17unsigned_integraljEDaT_T0_
_Z7CeilDivITkSt17unsigned_integralmTkSt17unsigned_integralmEDaT_T0_
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{
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    assert(divisor > 0);
  Branch (72:5): [True: 610, False: 0]

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    return dividend / divisor + (dividend % divisor != 0);
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}
Unexecuted instantiation: _Z7CeilDivITkSt17unsigned_integraljTkSt17unsigned_integralmEDaT_T0_
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/**
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 * @brief Left bit shift with overflow checking.
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 * @param input The input value to be left shifted.
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 * @param shift The number of bits to left shift.
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 * @return (input * 2^shift) or nullopt if it would not fit in the return type.
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 */
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template <std::integral T>
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constexpr std::optional<T> CheckedLeftShift(T input, unsigned shift) noexcept
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{
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    if (shift == 0 || input == 0) return input;
  Branch (85:9): [True: 0, False: 0]
  Branch (85:23): [True: 0, False: 0]

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    // Avoid undefined c++ behaviour if shift is >= number of bits in T.
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    if (shift >= sizeof(T) * CHAR_BIT) return std::nullopt;
  Branch (87:9): [True: 0, False: 0]

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    // If input << shift is too big to fit in T, return nullopt.
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    if (input > (std::numeric_limits<T>::max() >> shift)) return std::nullopt;
  Branch (89:9): [True: 0, False: 0]

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    if (input < (std::numeric_limits<T>::min() >> shift)) return std::nullopt;
  Branch (90:9): [True: 0, False: 0]

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    return input << shift;
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}
Unexecuted instantiation: _Z16CheckedLeftShiftITkSt8integralyESt8optionalIT_ES1_j
Unexecuted instantiation: _Z16CheckedLeftShiftITkSt8integralmESt8optionalIT_ES1_j
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/**
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 * @brief Left bit shift with safe minimum and maximum values.
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 * @param input The input value to be left shifted.
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 * @param shift The number of bits to left shift.
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 * @return (input * 2^shift) clamped to fit between the lowest and highest
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 *         representable values of the type T.
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 */
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template <std::integral T>
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constexpr T SaturatingLeftShift(T input, unsigned shift) noexcept
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{
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    if (auto result{CheckedLeftShift(input, shift)}) return *result;
  Branch (104:14): [True: 0, False: 0]

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    // If input << shift is too big to fit in T, return biggest positive or negative
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    // number that fits.
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    return input < 0 ? std::numeric_limits<T>::min() : std::numeric_limits<T>::max();
  Branch (107:12): [True: 0, False: 0]

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}
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#endif // BITCOIN_UTIL_OVERFLOW_H