git / moonbite-core / src/compat/assumptions.h · raw

// Copyright (c) 2009-2010 Satoshi Nakamoto// Copyright (c) 2009-2019 The Bitcoin Core developers// Distributed under the MIT software license, see the accompanying// file COPYING or http://www.opensource.org/licenses/mit-license.php.// Compile-time verification of assumptions we make.#ifndef BITCOIN_COMPAT_ASSUMPTIONS_H#define BITCOIN_COMPAT_ASSUMPTIONS_H#include <limits>// Assumption: We assume that the macro NDEBUG is not defined.// Example(s): We use assert(...) extensively with the assumption of it never//             being a noop at runtime.#if defined(NDEBUG)# error "Litecoin cannot be compiled without assertions."#endif// Assumption: We assume a C++11 (ISO/IEC 14882:2011) compiler (minimum requirement).// Example(s): We assume the presence of C++11 features everywhere :-)// Note:       MSVC does not report the expected __cplusplus value due to legacy//             reasons.#if !defined(_MSC_VER)// ISO Standard C++11 [cpp.predefined]p1:// "The name __cplusplus is defined to the value 201103L when compiling a C++//  translation unit."static_assert(__cplusplus >= 201103L, "C++11 standard assumed");#endif// Assumption: We assume the floating-point types to fulfill the requirements of//             IEC 559 (IEEE 754) standard.// Example(s): Floating-point division by zero in ConnectBlock, CreateTransaction//             and EstimateMedianVal.static_assert(std::numeric_limits<float>::is_iec559, "IEEE 754 float assumed");static_assert(std::numeric_limits<double>::is_iec559, "IEEE 754 double assumed");// Assumption: We assume eight bits per byte (obviously, but remember: don't//             trust -- verify!).// Example(s): Everywhere :-)static_assert(std::numeric_limits<unsigned char>::digits == 8, "8-bit byte assumed");// Assumption: We assume floating-point widths.// Example(s): Type punning in serialization code (ser_{float,double}_to_uint{32,64}).static_assert(sizeof(float) == 4, "32-bit float assumed");static_assert(sizeof(double) == 8, "64-bit double assumed");// Assumption: We assume integer widths.// Example(s): GetSizeOfCompactSize and WriteCompactSize in the serialization//             code.static_assert(sizeof(short) == 2, "16-bit short assumed");static_assert(sizeof(int) == 4, "32-bit int assumed");static_assert(sizeof(unsigned) == 4, "32-bit unsigned assumed");// Assumption: We assume size_t to be 32-bit or 64-bit.// Example(s): size_t assumed to be at least 32-bit in ecdsa_signature_parse_der_lax(...).//             size_t assumed to be 32-bit or 64-bit in MallocUsage(...).static_assert(sizeof(size_t) == 4 || sizeof(size_t) == 8, "size_t assumed to be 32-bit or 64-bit");static_assert(sizeof(size_t) == sizeof(void*), "Sizes of size_t and void* assumed to be equal");// Some important things we are NOT assuming (non-exhaustive list):// * We are NOT assuming a specific value for std::endian::native.// * We are NOT assuming a specific value for std::locale("").name().// * We are NOT assuming a specific value for std::numeric_limits<char>::is_signed.#endif // BITCOIN_COMPAT_ASSUMPTIONS_H