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author | Wladimir J. van der Laan <laanwj@gmail.com> | 2019-03-16 17:07:14 +0100 |
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committer | Wladimir J. van der Laan <laanwj@gmail.com> | 2019-03-16 17:11:14 +0100 |
commit | 2f501fb5c68d710ac9cbac0bfbdd163808c5076b (patch) | |
tree | 68795e431fe72ae4d6cdf71c9237d40fbfd20dc2 /src | |
parent | 165ea14efedab6158a3edf9f029a128db4659473 (diff) | |
parent | c7a7250302b60b78af39f39ee403d330c0cb7aa0 (diff) | |
download | bitcoin-2f501fb5c68d710ac9cbac0bfbdd163808c5076b.tar.xz |
Merge #15522: Document sizeof(size_t) assumptions and compiler assumptions in assumptions.h
c7a7250302b60b78af39f39ee403d330c0cb7aa0 Document assumptions about C++ compiler (practicalswift)
c7ea8d3236e7c1b0c198345cc78a6754338d3724 Add sizeof(size_t) assumptions (practicalswift)
Pull request description:
Document `sizeof(size_t)` assumptions and compiler assumptions by adding compile-time checks in `assumptions.h`.
Tree-SHA512: db46481eecad6a87718ae637a7761d39d32cfe6f95fc8ad2b3a52a3d966c2a05c8f540dd3f362721279816571b04b6cce2de9b3b1d17606d7b197126cd4a8d1f
Diffstat (limited to 'src')
-rw-r--r-- | src/compat/assumptions.h | 18 |
1 files changed, 17 insertions, 1 deletions
diff --git a/src/compat/assumptions.h b/src/compat/assumptions.h index 820c9b93d9..6e7b4d3ded 100644 --- a/src/compat/assumptions.h +++ b/src/compat/assumptions.h @@ -17,6 +17,17 @@ # error "Bitcoin 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 @@ -40,8 +51,13 @@ static_assert(sizeof(double) == 8, "64-bit double assumed"); static_assert(sizeof(short) == 2, "16-bit short assumed"); static_assert(sizeof(int) == 4, "32-bit int 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 sizeof(std::size_t). // * 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. |