These changes conforms to the C11 standard
References:
- 7.27.1/3 Components of time (struct timespec)
- 7.27.2.5 The timespec_get function
According to ISO/IEC 9899:201x (draft) <time.h> defines the timespec
structure and declares the timespec_get(3) function with TIME_UTC
definition.
According to a C++17 standard draft <ctime> offers the same interface in
the std:: namespace.
The timespec_get function modifies the timespec object pointed by ts
to hold the current calendar time in the given base. The standard notes
only the TIME_UTC base with implementation defined value, set it to 1
as zero is reserved for error handling. Once operation was successful this
function returns passed base, otherwise exits with zero.
The timespec struct was already part of the POSIX standard in <time.h>.
Enable this interface unconditionally in the header to allow to use it
in a code prior C11 and C++17 as an extension.
Review notes from <christos>
This header conforms to the C11 standard
Reference: ISO/IEC 9899:201x 7.15 Alignment <stdalign.h>
According to ISO/IEC 9899:201x (draft) 7.15 Alignment <stdalign.h> defines
four macros:
- alignas which expands to _Alignas
- alignof which expands to _Alignof
- __alignas_is_defined and __alignof_is_defined which both expand to 1
The _Alignas declaration appears as one of the type specifiers to modify
the alignment requirement of the object being declared.
The _Alignof operator is used to query the alignment requirement of its
operand type.
ISO/IEC N3242=11-0012 (C++1x) and ISO/IEC N3797 (C++1y) both note a header
<cstdalign> which defines only __alignas_is_defined and shall not define
the alignas macro. It misses the alignof case as it's probably based on an
older C1x draft, which defined only alignas. Assume that this is a bug in
the standard and treat alignof the same way as alignas in C++11.
Allow to define alignas and alignof in C++ prior the C++11 standard. It
might be broken but a nonstandard C++ compiler might support C11-like
_Alignas and _Alignof. Note that it's fatal for g++(1) v.5.4.
This header conforms to the C11 standard
Reference: ISO/IEC 9899:201x 7.23 _Noreturn <stdnoreturn.h>
According to ISO/IEC 9899:201x (draft) <stdnoreturn.> defines the
noreturn macro which expands to _Noreturn.
The _Noreturn keyword appears in a function declaration and specifies
that the function does not return by reaching the end of the function
body.
Design choices:
- don't implicitly break C++ code including this header with #error
C++11 offers [[noreturn]] which conflicts with C11 _Noreturn
- don't check for __STDC_VERSION__, everybody is free to reuse it with
a nonstandard compiler not conforming to C11 but supporting _Noreturn
gcc(1) and clang(1) support _Noreturn in -std=c99 and older standards
this follows <stdbool.h> choice for not checking for C99
- follow <stdbool.h> and declare the __noreturn_is_defined guard
- use a standard header guard (_STDNORETURN_H_), similar to <stdbool.h>
Reviewed by <pgoyette> and <joerg>
to come up with a better way to handle attachment-specific modules, and
possibly a better directory structure for modules in general, as the
current mechanism doesn't scale.
and PCI_IOC_DRVNAMEONBUS. the new ones also take a (autoconf) PCI bus
number, which allows lookups for any device on any pci bus node. use this
in pcictl which current reports the wrong values sometimes.
up next: use these in libpciaccess.
