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| author | Jonathan Wakely <jwakely@redhat.com> | 2019-06-18 12:39:43 +0100 |
|---|---|---|
| committer | Jonathan Wakely <redi@gcc.gnu.org> | 2019-06-18 12:39:43 +0100 |
| commit | 0c65926ffa960ddbe7df9ea86328f8905df861cf (patch) | |
| tree | 597b8d18820d74dc4f718ec184bdf2ab2798d236 | |
| parent | 5ed12b58ef022b5186edc6c31eb05addc828fd8b (diff) | |
| download | gcc-0c65926ffa960ddbe7df9ea86328f8905df861cf.zip gcc-0c65926ffa960ddbe7df9ea86328f8905df861cf.tar.gz gcc-0c65926ffa960ddbe7df9ea86328f8905df861cf.tar.bz2 | |
Avoid undefined behaviour in std::byte operators (LWG 2950)
* include/c_global/cstddef (std::byte): Perform arithmetic operations
in unsigned int to avoid promotion (LWG 2950).
From-SVN: r272415
| -rw-r--r-- | libstdc++-v3/ChangeLog | 5 | ||||
| -rw-r--r-- | libstdc++-v3/include/c_global/cstddef | 74 |
2 files changed, 33 insertions, 46 deletions
diff --git a/libstdc++-v3/ChangeLog b/libstdc++-v3/ChangeLog index 40d1b0b..4570ab1 100644 --- a/libstdc++-v3/ChangeLog +++ b/libstdc++-v3/ChangeLog @@ -1,3 +1,8 @@ +2019-06-18 Jonathan Wakely <jwakely@redhat.com> + + * include/c_global/cstddef (std::byte): Perform arithmetic operations + in unsigned int to avoid promotion (LWG 2950). + 2019-06-17 Jonathan Wakely <jwakely@redhat.com> * testsuite/20_util/allocator/1.cc: Add sized delete, which fixes a diff --git a/libstdc++-v3/include/c_global/cstddef b/libstdc++-v3/include/c_global/cstddef index 8c779ec..c94c938 100644 --- a/libstdc++-v3/include/c_global/cstddef +++ b/libstdc++-v3/include/c_global/cstddef @@ -121,70 +121,52 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION using __byte_op_t = typename __byte_operand<_IntegerType>::__type; template<typename _IntegerType> - constexpr __byte_op_t<_IntegerType>& - operator<<=(byte& __b, _IntegerType __shift) noexcept - { return __b = byte(static_cast<unsigned char>(__b) << __shift); } - - template<typename _IntegerType> constexpr __byte_op_t<_IntegerType> operator<<(byte __b, _IntegerType __shift) noexcept - { return byte(static_cast<unsigned char>(__b) << __shift); } - - template<typename _IntegerType> - constexpr __byte_op_t<_IntegerType>& - operator>>=(byte& __b, _IntegerType __shift) noexcept - { return __b = byte(static_cast<unsigned char>(__b) >> __shift); } + { return (byte)(unsigned char)((unsigned)__b << __shift); } template<typename _IntegerType> constexpr __byte_op_t<_IntegerType> operator>>(byte __b, _IntegerType __shift) noexcept - { return byte(static_cast<unsigned char>(__b) >> __shift); } - - constexpr byte& - operator|=(byte& __l, byte __r) noexcept - { - return __l = - byte(static_cast<unsigned char>(__l) | static_cast<unsigned char>(__r)); - } + { return (byte)(unsigned char)((unsigned)__b >> __shift); } constexpr byte operator|(byte __l, byte __r) noexcept - { - return - byte(static_cast<unsigned char>(__l) | static_cast<unsigned char>(__r)); - } - - constexpr byte& - operator&=(byte& __l, byte __r) noexcept - { - return __l = - byte(static_cast<unsigned char>(__l) & static_cast<unsigned char>(__r)); - } + { return (byte)(unsigned char)((unsigned)__l | (unsigned)__r); } constexpr byte operator&(byte __l, byte __r) noexcept - { - return - byte(static_cast<unsigned char>(__l) & static_cast<unsigned char>(__r)); - } - - constexpr byte& - operator^=(byte& __l, byte __r) noexcept - { - return __l = - byte(static_cast<unsigned char>(__l) ^ static_cast<unsigned char>(__r)); - } + { return (byte)(unsigned char)((unsigned)__l & (unsigned)__r); } constexpr byte operator^(byte __l, byte __r) noexcept - { - return - byte(static_cast<unsigned char>(__l) ^ static_cast<unsigned char>(__r)); - } + { return (byte)(unsigned char)((unsigned)__l ^ (unsigned)__r); } constexpr byte operator~(byte __b) noexcept - { return byte(~static_cast<unsigned char>(__b)); } + { return (byte)(unsigned char)~(unsigned)__b; } + + template<typename _IntegerType> + constexpr __byte_op_t<_IntegerType>& + operator<<=(byte& __b, _IntegerType __shift) noexcept + { return __b = __b << __shift; } + + template<typename _IntegerType> + constexpr __byte_op_t<_IntegerType>& + operator>>=(byte& __b, _IntegerType __shift) noexcept + { return __b = __b >> __shift; } + + constexpr byte& + operator|=(byte& __l, byte __r) noexcept + { return __l = __l | __r; } + + constexpr byte& + operator&=(byte& __l, byte __r) noexcept + { return __l = __l & __r; } + + constexpr byte& + operator^=(byte& __l, byte __r) noexcept + { return __l = __l ^ __r; } template<typename _IntegerType> constexpr _IntegerType |