mirror of
https://github.com/bitcoin/bitcoin.git
synced 2025-01-12 21:02:38 -03:00
57 lines
2.7 KiB
C++
57 lines
2.7 KiB
C++
// Copyright (c) 2009-2010 Satoshi Nakamoto
|
|
// Copyright (c) 2009-2020 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 "Bitcoin cannot be compiled without assertions."
|
|
#endif
|
|
|
|
// Assumption: We assume a C++17 (ISO/IEC 14882:2017) compiler (minimum requirement).
|
|
// Example(s): We assume the presence of C++17 features everywhere :-)
|
|
// ISO Standard C++17 [cpp.predefined]p1:
|
|
// "The name __cplusplus is defined to the value 201703L when compiling a C++
|
|
// translation unit."
|
|
static_assert(__cplusplus >= 201703L, "C++17 standard assumed");
|
|
|
|
// 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 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
|